@YouJustDoYou - thanks for the womansplaining! 🙂
Let me put it this way. These days, I'm actually a big fan of separate finances. That comes after getting out of an abusive marriage, where she ultimately turned violent. She was financially dependent on me. Our salaries were paid into a joint account. The only things we had separate were a couple of savings accounts, purely because ISAs can only be in one name. And when we split (after thenPolice had been involved following her assaulting me again), she emptied all those accounts and gave the money to her mother. Money that I'd earned. I would never marry again, and I wouldn't want joint finances again, beyond those required to pay the bills.
So, within that context....if a woman is earning and supporting herself, she can do whatever the hell she likes with her money. If that means creating a running away fund, she's welcome to do that. Although I may start questioning whether this is the right relationship for me, if my partner is constantly planning for leaving me.
If, however, someone were financially dependent on me, and - without my knowledge or agreement - started secretly stashing money away into her running away fund, I would view that as stealing from me. And that relationship would be over, there and then. No amount of saying "but loads of men are really abusive" would make that okay. Because I'm not abusive. So there would be no excuse for stealing from me. Which is what secretly taking joint money, or money that I've earned, and putting it into an account that I can't touch and am not supposed to know about, is.
You can shout about "but men are abusive" all you like. And yes, some are. If a woman is actually in one of those relationships, fine - do what you need to do to get out. Totally understand, and totally support that. But if you're with a good man, and feel the need to deceive and steal from him to build up your own nest egg, then I assure you that you're on the wrong side of the moral debate there.