One of my Daughter's confessed something and I'm not sure how to handle it

I left my abusive Ex husband some months ago and I've been struggling to raise my three teens my son (16) and daughters (both 15). One of my daughter's recently confessed that she's been in contact with her Dad and he's been asking her questions and she's basically been spying for him and I know I'm being dramatic but that's the only word that comes to mind. I asked point blank what things she told him. I'm angry now and I told her to go to her room before I said something I'd regret.This happened yesterday and I've been purposefully avoiding her because I understand that she loves her dad but he's very dangerous and the idea that she'd be giving him information he could use makes me mad. Her brother and sister found out to and did not take it well.I'm trying to be fair but understanding her reasoning does not make what she did hurt any less. I honestly partly want to blow up at her and the only thing that keeps me from doing that is the fact that I've been giving her the cold shoulder.I mean I know I'm probably reacting badly but I'm not perfect I know that part of me wants to do the "right" thing and comfort her but an even bigger part of me is too hurt to really want to. I'm angry at her for betraying me and more importantly her siblings and I'm mad at myself for not seeing this coming. I mean how can I rebuild trust with her? via /r/Parenting https://ift.tt/2D3RTPO