To the OP, most of us live in the US or UK where the norm is 40-60% of assets and 50/50 custody. She's stated she doesn't believe she could even get a divorce without your permission. You repeated that, said she told you about the affair hoping you'd grant a divorce, but say there are other ways you think she could get a divorce, but you don't sound certain and she may not know of these.
I don't think you want her to stay with you because she feels trapped. In DB terms, set her free. The next time she brings up D, I would let her know you don't want one, but if she did you would grant permission and are committed to a fair outcome where you both see the kids and are provided for. (I would NOT spend any time working out what that looks like.)
Know your rights so you aren't fleeced. See a lawyer. Ensure she has access to one, too so she's not fleeced. The goal isn't the best possible outcome for you. In most countries, I do not emphasize this, because the courts ensure balance. If you want marriage to be a choice she makes because she wants to be with you, she has to be free to leave. In DB terms, don't do any legwork for her to divorce you, but also don't stand in her way (e.g., by withholding permission).
I have never said she cannot have permission, I don't believe this is even possible. She is saying that I have to come to the lawyer with her and tell him I want a divorce as well. I have said I will not do this, but she is free to proceed any way she likes. I think this is inline with what you are saying about not doing any legwork?
She also is fully aware that she can go to the UK for a divorce, she has mentioned that she could do this many times.
