First of, kudos for sticking with your wife through all of this. Transition is a terrifying emotional whirlwind, in my limited experience, and it's very easy to get discouraged.
I'm speaking as a trans man in a relationship with a cisgendered man. Hopefully, some of the women in relationships with women here on the board will also be able to give their perspective as well. I'm going to tell you a little of what's going on inside my head. Maybe it can give you some perspective on what's going on with Jill.
I get very uncomfortable going out in public with my boyfriend. There are a bunch of reasons for it. I'm in the process of transition, so people don't see me as the person I wish to be seen as, especially up close or when I speak (I'm pre-HRT and I have a very feminine voice). I come from a very conservative part of the US, so I worry about what people will think of seeing a woman dressed as a man. Then I worry about the fact that some people will see me as a man holding the hand of another man. I want to postpone a lot of interaction--especially meeting my boyfriend's friends--until I've transitioned further. I want to meet them as his boyfriend, rather than as someone who looks like his girlfriend. All this conflict, pressure, and delf-doubt make me reluctant to go out of the house, interact, meet people, and so forth. Sometimes I feel like it isn't worth getting out of bed at all.
I started dating my boyfriend as a woman. What I appreciate most is the fact that as I started to transition, he did not change how he treated me in public at all. He was never "gentlemanly" with me when I was trying to be a woman. He's a naturally sweet and feminine person, and okay with himself that way, so he never tried to enforce gender roles. That made it very easy to be his boyfriend rather than his girlfriend. I can definitely see that being an issue, if you and Jill previously fell into gender roles of any kind. Transition kind of throws that dynamic through a loop.
Other than that, my boyfriend frequently reminds me that he wants to be there for me. When we go out, he still holds my hand, leans on me, kisses me, and so forth. Honestly I think he does it a bit more nowadays, because he knows I'm shy and uncomfortable. He compliments me on masculine or genderless qualities, rather than on feminine ones. He listens when I need to talk. He reminds me that he loves me. Those things all help me have a stable, safe base during what has become the most stressful and confusing period in my entire life. I know that no matter what else happens, there is one person on this earth who loves and supports me unconditionally. I really, really need that security in order to have the strength to keep going.
Because I rely on him so much, when he slips a pronoun by accident, it's devastating. It makes me feel completely and utterly invalidated, even though I know on an intellectual level that he sees me as male, but is trying to break a five-year habit of seeing me as female. I know he supports me. But when it seems, just for a flicker, that maybe he doesn't really, it crushes me. It's not really rational. It just is.
I worry about the stress I cause him, too, and I try to be there for him as much as he is for me. But it's hard being supportive during a time when I feel so very needy of support myself. I feel like a leech sometimes. But the thing is, I really need that support, even though I worry it makes me seem selfish. After I've put most of my energy into staying sane and keeping myself safe, I don't have a lot left over to pour back into our relationship before I run dry. It means that for now, my boyfriend has to put a lot of effort in to our relationship and not expect as much back as I once gave.
But, since we've been together a long time (6 years), I figure we do trade off. I've supported him through some major family drama in the past. Now he's supporting me. Later in our relationship, the seesaw will swing back, and I'll be supporting him through something again. I can see how easily he could become resentful of me if I had never supported him much in the past. Or how I could easily get resentful of him if he weren't so supportive now, considering what I've done for him. I think it's important to recognize that sometimes in the give-and-take of a relationship, it seems like all you do is give. Just so long as the other person gives when they are able to, things will eventually level out.
I also know that things are getting confusing for him, in that I am changing. I like to think I'm becoming "me," but I worry that "me" may be unrecognizable compared to the person I tried to be as a woman. I can only imagine how strange and unsettling the process is from the perspective of a partner, given how weird it is for me. I try to keep my boyfriend in the loop. But sometimes I'm just so uncomfortable about things (like my body) that it's really hard to express myself, and I avoid it. It sometimes feels impossible or even pointless to talk about these things when I feel so insecure and am so frequently invalidated throughout the day by other people. It's helpful when my boyfriend asks me things. I'm more likely to answer questions than bring things up on my own. I can't expect him to read my mind and ask the right questions, though.
That's all I can think of. I hope that was helpful in some way. Feel free to ask me questions.