Hi Georgia,
While I don't have human children (just cats), I have been married for 10 years this year (with her for 12 years), and your situation sounds fairly familiar. When we met, she told me that she liked girls, too, and that made me feel excited and safe with her. I've been full-time for a little over a year now, and have been on HRT for almost 1 month now. I used to wear women's clothing and makeup fairly regularly, but eased back because of comments that she would make. We used to get into arguments sometimes before going out if I was presenting too femme, because she wanted to be the feminine one. I think she felt threatened or invalidated. She never said that she would leave me, but she did say that she married a man. All this contributed to it taking me so long to come out. I eased into it, too. I was living as gender fluid for maybe 2 years before coming out as trans*. It took a lot of open, honest, and often painful discussions, but we are in a very good place with my transition. Once she realized that this is not a choice, she really got behind me. She is my best friend and always has been. It helps that we have both been in therapy for years now, so much of the time, we would work things out in our therapist's office - but we also talk at home a lot, too.
We make time and effort to check in with each other fairly regularly and keep an open dialogue. It takes a lot of work, but it's worth it. I was scared at first that this might kill my marriage, but I couldn't keep living as someone that I'm not anymore. Now things are pretty good and she makes comments to me about how pretty I look, and we share clothes now (well, we always have a little, but now she lets me wear the good stuff, and even gives me things to keep). The biggest hurdle, aside from just coming out, has been HRT. I didn't think I wanted to do it at first, but that changed quickly. She was very nervous about it, as was I, but here we are, and so far so good
Anyway, this post is getting long now, so I apologize, but, YES, it was absolutely worth it!
I've lost some people in my life, but honestly, good riddance to them. I still have such a long way to go, but I'm feeling so much better now and am slowly learning to finally love myself.
It's going to be completely different for everyone, but I would suspect that if you approach the topic gently and slowly, your wife will support you. I mean, you are still you, after all. You won't know unless you try. I hope the best for you, and there is a ton of support on here.
xo,
Rain