I this week met a fully tri-lingual 6-year-old (English, Spanish, Romanian). The determining factor is apparently what the kid hears at the age of 4 to 7 months - she has to hear each language spoken regularly. I believe there is no demonstrated limit to the number of “cradle” languages a child can learn this way.
Multilingualism:
Eh, not my family, but every Andorran over the age of 18 I’ve met was at least pentalingual. True, it may have been “pentalingual for business purposes”, but they were at the very least trilingual for everyday purposes. Note that they have the advantage of living in a trilingual society, and that those three languages are extremely close to each other (French, Catalan and Spanish - Spanish is not an official language of Andorra).
Bilingual is fairly common; of course it’s both easier and more succesful if there are other bilingual people in the area, schools, etc.
I grew up monoingual but hearing my mother speak a different language with her mother, sister and nephews - not to us. I did have the advantage that it was a language very close to my primary, but still, if it had been very different, I simply would have asked “what does [strange word] mean?” more often. Eventually I was able to learn to speak it fluently, too, once I was living in the area where it is spoken.
I went to a French-immersion school for 3 months when I was 3yo. Thank Og, Ogette, the infinite Mercy and the job offer Dad got in a different town, I got taken out of that hell hole - but Mom was enormously surprised when years later I mentioned I wanted to take up French lessons again, she quizzed me on the stuff I’d learned at age 4 and I still remembered it thank you much: I hadn’t used it for 14 years.
Arm strength: sounds normal for her age, if the pediatrician is happy she’s fine.
Milk: Yoghurt, danonino (there have to be similar things in the UK, I just don’t know the brands), bananas mashed in milk were all very popular with my nephews at a similar age.
Noises: it’s experimentation. She’s experimenting with her vocal chords. Apparently, one of her findings has been “cool, if I make this noise loud enough I get attention!”
IOW, sounds like a perfectly healthy kid who’s got you both quite wrapped around her little finger 
Can’t speak to this much because we haven’t made a huge concerted effort to get them trilingual, though we do speak to them somewhat frequently in Hindi or Spanish in addition to our native English. My son, five, has had no trouble picking up all three, and I’ve heard from friends who do make a make a stronger effort that it’s not generally a problem.
I agree with the tummy time suggestion. Our daughter was hell bent on cruising first, so her arms weren’t quite as strong as her legs. Still, it doesn’t hurt to get your pediatrician’s opinion, if only for your peace of mind. Most issues like this tend to be non-issues, but you never know, and if there is a problem, best to catch it early.
How much does your wife produce? It sounds like she pumps - does she have a good pump (usually an electric one is best, but response can vary drastically from woman to woman) or simply not respond well to it? I agree with the additional nursing, perhaps with an extra pumping session or two thrown in. And, if it makes you feel any better, we had the same problem with my daughter, only she outright refused formula when I was concerned she wasn’t getting enough milk. She was only drinking 3 3-4 ounce bottles while in daycare, but it turned out that it was enough for her. My supply dwindled enough that the pediatrician recommend we start shifting her to whole milk at 10.5 months. It took about a month and a half to get her to take it anyway, so it didn’t make much difference. Anyway, keep trying with the bottle; we used Tommy Tippee bottles. They were the only ones she would take.
She’s totally screwing with you. My daughter used to play dead in her high chair. It scared the living crap out of me. She would pretend to choke (she had choked once on a grape quarter that went down the wrong way and got an immediate reaction out of me at about 8 months), then slump to the right and just hang there. I would panic, run over and check on her, and she’d sit up and laugh hysterically and clap her hands. Now she sprawls on the floor on her face and doesn’t move if I poke her. I don’t know where she learned this, but when timed correctly, it scares the ever-loving shit out of me.
The fact that you react will probably make her continue, at least until she decides to move on to a new noise.
The key thing on multiligualism is that the child has an anchor person for each language. In your case, Italian for your and Chinese for your wife. When speaking to each other or a group environment, then you can switch from the anchor language. But don’t speak sometimes in Italian, sometimes in Chinese and sometimes in English 1:1 with your child.
My wife is Chinese and kids were born and raised in China. I always spoke English, Mom almost always spoke Mandarin (she is a native shanghaiese speaker), grandma often spoke Shanghaiese. All of our kids, even the barely verbal autistic one, did active code switching. Eg, cacausians spoke in English, Asians in Chinese, elderly Asians in Shanghaiese. The Shanghaiese is by far their worst language but they seem to understand it reasonably well.
Anyhoo, that’s my experience and matches the research I’ve seen. In other words, one parent, one anchor language.
I know a boy (well, he is a man now, but I knew him as a boy, teen and a 20-something) who grew up quadrilingual. His mother is Argentinian and spoke only Spanish with him (also to her husband), the father is native German speaking and spoke only German. Obviously, his parents each understood the other language. He then went to bilingual (French/English) schools in Montreal and learned both of those languages. I can testify that he has native fluency in English and I can only assume in the other three. He is currently in business in Argentina in partnership with a cousin.
I also know a fairly retarded boy who speaks English, although not well (I think that is on account of the retardation), Spanish (both parents are Argentinian and they have arranged that when they die a cousin in that country will care for him–I once met her and her English is poor), and he reputedly also speaks French. He is grown now and, while he lives at home, he spends most of his time in a sheltered workshop, as his parents both work (both are professors).
So the ability to learn languages seems almost unlimited. The second case seems most extraordinary.
I’m bilingual, having grown up with a mom who spoke to us kids only in French and a dad who spoke to us only in English. It actually took a few years - 4-5-6?- before each child clued in and realised that our parents spoke to each other in English, but that Dad also spoke French! As it is today - I’m 29 - I still speak only in English to my father, and maybe 85% of the time in French to my mom. The times when I switch to English are “salad times”; either a story/emotion I’m relaying feels more English, or the story involved technical details/experiences that happened to me in an English environment.
Family dinners involve pretty much everyone at the table switching rapidly between languages from one conversation to the next, or even all in the same conversation, but simply switching as we address certain people. When my FIL visits my family, he’s blown away by it; his English isn’t nearly good enough to try and keep up.
From my experience raising a bilingual child, my studies of psycholinguistics, and the reports of many friends who have attempted to raise bilingual children, one thing keeps coming up.
Children will only learn languages that they need.
If mommy speaks Thai but also speaks English extremely well, and daddy only really speaks English, and the child lives in an English speaking country, the child is unlikely to learn very much Thai. If the child has playmates that prefer to speak Thai, though, that can change things.
Multilingual children that I have known had solid reasons for each language. I knew kids that spoke Persian at home, Hebrew in school, Arabic with their friends, and English with their religious group. These children became quite competent in each language, at least as far as speaking goes.
That is something that worries me, and I was thinking of posting about it. I remember reading on an internet forum, probably here, the post of a Korean-American person that said he (or she) just stopped speaking Korean when a small kid because they felt it was “not useful”, as all of their friends spoke English. He (or she) also wrote about how much the decision was regretted when they became an adult.
And there’s only me speaking Italian here. We have plenty of friends speaking Chinese, and many of them have children or plan to have them. Italians are in shorter supply in my social circle, and those that I know are here for a short spell (PhDs, temp contracts, work placements and the like) and plan to move away.
Um, you got the attribution wrong on that quote. It was Lasciel who said what you quoted, not me.
I remember the screaming. If you are in the room and can see her, I suggest foam earplugs. They reduce some of the fiercer qualities of the high shriek, yet still allow you to hear what is going on around you. Earplugs saved my sanity.
Also try introducing new sounds for her to try. Dr. Seuss’s book, “Mr. Brown Can Moo, Can You”? is full of good ones. MY 18 year old still makes some of those sounds.
When my little girl was 6 months she also got fussy about food. Let her play in some mushy food and suck it off of her hands. Rice ceral can be mixed with formula or breast milk to a pudding like consistancy.
If you are holding her to feed her she may not like the position of her body. My little girl did not like to be held. I propped her up to feed and play with her and things went much better
Don’t you just feel like King of the World when she laughs?