My terrier/chihuahua does it. And she will often back herself up a tree, and holding herself in place with her left leg, she stretches the right one out high. Bitch pees where she fuckin’ wants.
When dogs are learning things, they watch what other dogs do and it is possible that your female dog was only exposed to male dogs when she was a puppy and picked it up from that.
Bob
Our girl does the same - squat to relieve the bladder, lifts her leg to mark. She thinks she’s the alpha female, and I’ve always assumed that was why.
Thanks for all the info folks…ignorance fought.
When I was a kid we had a desexed female who would pee on dead toads that way. We had a place at the beach and there was a bit of a plague of toads at the time. They would get squashed on the roads by cars (probably deliberately). She would run from one squashed body to the other and pee holding up her back leg.
Just to balance things out, my current 20 month old desexed male still pees like a girl 
My own dog lifted her leg her entire life when marking; she squatted only when really needing to relieve herself. Spayed, mixed breed whippet-something.
Apparently gender identification isn’t limited to humans.
My fat speutered girl Chi started doing this after my heartdog passed away. The heartdog also lifted a leg during her squat. Both are/were alpha bitches. The fat Chi was raised by the heartdog.
As far as pee-mail goes my boy Chi loves to sniff the tires of our vehicles and find whichever had went out to the shop last. He smells the “wall posts” that the boy dogs out there left and sends back one of his own. It’s hilarious when 3 or more vehicles come home scented because by the last one you can see him really concentrating to get a few squirts out. All 3 boy dogs are speutered.
Fat girl also marks over the other 2 Chis’ pee (a girl and a boy) and then the boy Chi pees over that and then I call them all in because I “worry” they’ll dehydrate themselves.
Thank you for adopting “pee-mail.” 
Mine kind of lifts her leg with marking on a tree sometimes. Mainly she’s solidly on all fours. She’s the alpha dog of the entire planet in her own mind (and she wasn’t that far off when she was young).
Is there a right or left leggedness in dogs or those special bitches that lift their legs? I’ve long wondered this.
Leet the Wonder Dog[sup]TM[/sup] has no particular preference when lifting a leg - right alternates with left pretty randomly. He (a neutered male) also will squat to pee when he just has to go, and lift his leg when being territorial.
Often the territorial part is a wasted effort. His tinkle marksmanship isn’t all that it might be, and he is commonly marking his own foot as his territory, and that was never in question.
Regards,
Shodan
Sounds like me and a lot of guys. Wives, amirite?
We had a male dog, and then adopted a female rescue who had spent her entire life in a puppy mill cage. When she started going outside with her new brother, she imitated him by lifting her leg. After we lost him, she gradually went back to the lady-squat.
Loki(female spayed mix-breed) does something gross.
When we are out on the pontoon boat and we go ashore so dogs and crew can relieve themselves, she will go out into the water (up to her belly) and shit.
Explain that weird behavior!
She’s ashamed to let the other dogs see her in that outfit.
Regards,
Shodan
My female Lab has always squatted.
On the other hand, there have been multiple episodes of her vigorously humping her bed.
Which I can’t understand, since she’s spayed. 
Animals masturbate. (insert “if I could reach” jokes here)
My neutered male Chi humps pillows… my spayed female fat Chi humps him and any of the cats who will put up with that. The male intact cockatoo humps toys. The alpha cat (male, neutered, 20# brown tabby) humps the other cats.
Some of it is dominance but some of it is plain old “that feels good”. At least judging by the smiles on the 2 Chis’ faces as they pump away.
True story. A couple of weeks ago I was talking to a lovely woman on a hike. She was telling me her female puppy did a front feet handstand to pee when right on cue, she did just that. Bizarre.