Seeking advice from those who have blended families

Especially from those toward the older end of the spectrum, but I’ll entertain anyone’s advice. I am looking for strategies and techniques for dealing with the inevitable conflicts and problems that might arise, not advice on whether I should do it or not.
My girlfriend and I plan to get married and move in together soon. I am looking forward to living with her, but I also find I have a lot of uncertainty about what it will be like. It’s causing me some angst.
She comes with a daughter who is almost 16. Daughter is somewhat awkward and introverted – I find her to be a bit whiny and needy – but she is overall a good kid. She also has a son of 19 who I like a lot – he lives with his father and is struggling with typical problems of that age in trying to decide what he wants to do with himself in terms of school and career.
I have lived alone since my divorce 5 years ago. My son of 23 is off at college most of the time, but he has some disabilities due to a massive stoke about 5½ years ago. I am hopeful that he will eventually lead an independent life, but I’m not certain what his future will be like.
After living alone for 5 years, I’ve become pretty set in my ways and accustomed to doing what I want to when I want to. It’s nice in some ways, and not healthy for me in other ways. Not enough social contact, bad lifestyle habits such as drinking too much, etc. But at any rate, combining families will be a huge lifestyle change for me. Hence my seeking advice from strangers on the internet. Well, you’re not exactly strangers, are you?

  1. What can I do to lessen the impression that they are moving into my house as permanent guests? I want this to be our house, after all. My plan so far is to gut as much of the place as I can, reconfigure other things, and, combined with her furniture and fixings, make it into someplace that looks new, not like my old place. What else, though? Emotionally, what sort of changes happen?
  2. Any advice for dealing with teen aged girls? Daughter seems to be growing up nicely. She likes school, has a few close friends, is not into the drug scene. She went through a big gender questioning period when she started high school – it seems to be a required course at her particular school – and was a boy for a while, now back to girl. Having raised only one son, I have no experience with the species, and the daughter is something of an enigma to me.
  3. What else? What am I overlooking? What should I be asking about if I had the benefit of experience in combining families? I’m interested in hearing about unexpected problems I haven’t even thought about. What worked for you? What would you do differently? What resources did you use when you needed help? Feel free to PM me if you’d rather.
    Thanks, dopers.
    Arrendajo

Discuss with your girlfriend and come to an agreement as to how you’ll be parenting her daughter (will you have equal say? what forms of discipline does she use? is it OK for you to discipline her, to what degree, when should you defer to mom? etc). My mom moved my (now-ex)stepdad and his 20-year-old brother into our childhood home when my sister and I were in our early teens. It was a very bumpy road because, as far as I could tell, they never came to an agreement about this. Sometimes he was a hardass, other times he was like a big kid. Sometimes he’d lay down the law, other times he’d defer to my mother, other times he’d participate in/instigate shenanigans rather than condemn, other other times he’d lay down the law only for my mother to countermand him after the fact. The inconsistency led to a lot of instability and emotional outbursts from my sister and me.

Being older now than my stepdad was at the time, I can appreciate how difficult it was from his perspective. It took me a long time to move past the resentment, though.

Thanks Rachellelogram. This is one area we have talked over pretty well. I’m a big believer in household rules being C2F2: Clear, consistent, firm and fair. I have no desire to be a surrogate father – her dad lives in town, and I have been careful all along to neither be her buddy nor parent. At her age, she’ll only be living with us for a couple of years, which could fly right by if we get along well or could be a miserable slog if we can’t. I would like to be a stable, parental influence in her life, helpful but not intrusive. She is difficult to read, for me, so I’m not always sure where I stand with her.

Sorry I can’t help. I like my families…ready for it?
On The Rocks!

Ok, I’m outta here. I need to go take a shower.

Do this with their input. Involve all of them in the decisions to the extent they’re interested in it and can; delegate some things to them. In your daughter’s room, she should be able to point out which furniture she wants to keep, what would she like to toss, what would she like new. When we moved to the house where my mother now lives, I was allowed to choose a table for my new bedroom: what Mom was looking at was roll-up desks (which look pretty but have no actual space), what I picked up was a 1m*1m table with a very smooth surface which worked great as a draftsmanship table.

Even though any visit by the sons will be as guests, things like having helped choose the closet in the guest room make it feel more like “home” and less like “hotel my parents”. And for all of them it’s a good opportunity to learn how to shop for furniture: I’ve known many people who hadn’t done it until they were getting married and each of them ended up buying things that a couple of years later had them saying “what was I thinking?” You weren’t, the salesman was.

Thanks for the advice, Nava. Both mother and daughter are into Mid-century Modern, like me, so this will be a fun project. Daughter is quite the minimalist and basically wants a bed and desk in her room, and that’s all. I’ll make sure she knows she is free to paint and decorate however she wants. She has a good eye for design and style, so I actually value her input.

I like my families too, but after living alone I am afraid I’ll turn into a hermit or reclusive crank and be impossible to live with. I want to make sure I’m ready for it, hence the advice-seeking.
Squeaky clean?