BVF, I hope you and your lawyer can take that bitch down. I'm with Tala, not all women are bitches, but there are some that are...and your ex is definitely one of them. I'm so happy for you that you got your kids back, though -- I was was glad to read that when you posted about it.
My ex also threatened me with shit when we were divorcing -- my little girl came home one time and told me "Daddy said I'll be living with him soon cause he's gonna put you in the hospital so bad you'll never come out." He also said that he'd take custody away because I'd been treated for depression (in other words, he'd say I was crazy) and because I was a witch. (The bastard was also Wiccan, but he was going to pretend to be a straight-up fine young Christian man so he could take my daughter away.)
I took him to court first, and he got an ass-reaming from a nice judge about what a fucking rotten father he was. I wish I'd videotaped it.
He ended up getting his paycheck garnished for non-payment of child support, and when he realized I was going to play hardball and not cave under to him, he took off. He hasn't seen our daughter for three years now, and she's better off without him...just like I have no doubt your kids are so much better off with you. Don't let her get away with this crap -- it sounds like you've got a good lawyer, so use that to your best advantage. She sounds like a psycho, and she doesn't need to be anywhere near your kids.
Good luck, man...