No, she's not, so now it's time to take it seriously. There's no way in hell she should take the kids with her, as SHE is the one who has left the marriage.
And absolutely not, your daughter is too young to decide for herself and it's not fair to put her in that position (I think 14+ can decide for themselves).
I think you need to seek some free legal advice, ASAP, or figure out if there's a family member or someone from which you can borrow a retainer for a GOOD, "men's rights" family law attorney.
At a MINIMUM, you should continue to make your position clear to her of "you're not removing our daughters from their home. If YOU want to leave, that's your decision, but they are staying here." Say it calmly, but firmly, and NOT in front of the kids. If she challenges you on it, say "OK, I was hoping you'd be reasonable. I guess not," and say nothing more. Let her believe you're seeking legal recourse. If she says something like "I know you can't afford an attorney," just say "You continue to underestimate me, and that's a mistake."
Also, send her something registered mail, return receipt, informing her IN WRITING that you do NOT consent to have your children removed from the home.
