So, taking things in order. I'm gonna start by apologizing for doing the trans thing and using she/her pronouns. I understand it can be hard, but I really cannot do otherwise.
The first thing I feel is I'd like to untangle several parts of the "lying" question. Is a trans woman being masc before coming out a lie? No, absolutely not, it's a common coping mechanism, especially in people who, just like me, have suffered abuse in childhood for being gender-nonconforming. Think of a woman having grown up in a very conservative environment where a lot of what we associate with "femininity" in the very superficial sense of the term was heavily repressed or forbidden, and trying to figure this out as an adult. Or a gay woman from a similar background. Trying to attach yourself to fatherhood as a way to salvage what you can from your assigned identity is also a common coping mechanism. However I feel like the idea of specifically dating trans women with a "strategy" that it makes staying together possible is, if not completely outlandish, an issue to be confronted: I do hope that what she sees in you is more than bisexuality. If not, there's a serious problem.
Second, is her entire persona a lie? Absolutely not. As I transition, I realize how much stuff is associated with gender, that turns out to just be about a person's personality and material possibilities. Let me give you a mundane example: videogames are (wrongly) considered a "boy's" thing, and I sure used to play a lot of videogames as a young person, and still enjoy them. My personality hasn't changed in that regard, but being a woman, I am expected to care for my relatives more, I do more household chores, I have less money, and take a lot of time in my day doing community care. As a result, I almost never play videogames at all, but my character hasn't changed, my material life has. Most of the stuff I was liked for as a man (my cooking skills, my bookishness, my liking for the outdoors, for animals, my curiosity, my attempts to dress elegantly, my silly singing and dancing, my sense of humour and love of puns) are still there. If anything, they're even sharper because much less of my mind is busy dealing with dysphoria. Leading me to my final point.
I'm returning to my comparison of being a gay girl who's lived until late in a conservative environment. Imagine such a woman trying to "be a lesbian". She would probably have a head full of stereotypes about what that is like. She would probably have to undo a lot of internalised homophobia. In a similar way, trans women are often denied femininity from a young age. In fact, the only outlet for many young trans women is the type of sexual representations cissexism loves to produce: horrific, degrading porn about us and our bodies, endless discussions about breasts, silicone breasts in particular, vaginas, "The Surgery", the way we dress, especially if it's a little bit sexy. And sex is the only reason anyone seems to accept we might want to transition in the first place: when I came out to my oldest friend, she asked me if I knew I could have sex with men even without being a woman myself. As if that was ever the issue! If you had asked me what were "feminine experiences" at the time, I would probably have relied on silly, frivolous stuff myself: skirts and polish, that sort of crap. We're later on and I would just honestly point to my whole life and say "Well a woman is all of that complicated, contradictory shit that happens to me from the moment I wake up to the moment I fall asleep, and also what happens when I sleep". Mostly I would say it's being constantly afraid of men in public space, to be honest, but that's not important right now. Early transitioning trans women are often cringe. They're learning.
As to your final remark, regarding chores and stuff, I'm sorry but regardless of gender she's a grown ass adult and you both have kids you take care of. She should do her part.
