Not exactly sure what you're asking guidance for, I'm afraid, Kris >.<
But, I think whether she's there in spirit or not, could affect how you want to feel.
When I was younger, I wasted a lot of food, and was a very picky eater. My older brother took it upon himself to eat the food no one wanted, and hated things going to waste. After he passed, it seemed like the least I could do to be a better person like he was is also try not to waste much(if any) food, and have done so.
My brother also suffered from gender dysphoria throughout most of his life, whereas I felt depressed but can't say I really understood or noticed my own dysphoria until long after he was gone. A part of me even wondered if he's living through me. Well, in a way, he totally is, because I looked-up to him. I wasn't really raised by my parents, moreso he raised me, and my life closely followed his own- so it might just be natural to grow up like the one you were taught by.
Why I'm saying any of this is because I think whether or not the twin is actually physically inside you or just with you in spirit, you can make it so by the presence of mind alone. It might help your convictions or justifications of certain things you decide to do. Part of it, too, if you ever feel like self-conscious or guilty about something about yourself, subconsciously you might try to put it on your twin, too.
I did something similar when I learned about the pregnancy drug DES(sorry I dont remember the details about DES beyond it can cause cancer in female embryo, and cause gender dysphoria in male embryo) from Tatiana and others. For some, it was a chemical that helped shape their brain in embryo that caused them to be transgender; and I think, at least for a time, I kind of wondered if the same were the case with me. Sometimes it's hard to face truths, and we look for reasons elsewhere. Sometimes even just for fun, like toys having some bearing on your gender identity like Amaki(I think), or being born during certain times of the moon like MaryT said.
