child on child sexual abuse, survivors? can you help me please?

[needadvicefast]

my 5 yr old dd has been sexually abused by another 5 year old girl, it's been going on for at least 6 months, there's no doubt about her disclosure, social services are involved with us and the other child. She is extremely traumatised and I think we've been managing to help her but tonight I stopped her from messing with dd2s (age 2.5) legs and lifting the back of her nappy. She is saying "I think it's right because B (other girl) did it to me." She has agreed to tell me when she wants to "mess" with her sister before she does it and obviously i'm not planning on leaving them alone together for the forseeable but how the hell do i deal with this?? We're waiting for mental health help but have been told it's likely to be up to 6 weeks before anything happens. If anyone has any insight into what she's going through or how to help her deal with the fact that this behaviour has been "normalised" for her I would be extremely grateful.

[BoysAreLikeDogs]

can you ring someone like Childline for immediate advice?

[needadvicefast]

Both dds in bed now, have dealt with it toight by telling dd2 to shout for me and tell dd1 "no" if she messes with her nappy, dd1 has agreed to tell me when she's thinking about it so i left it at that for tonight. Childline not too helpful last time i called, there's a helpline for mothers of sexually abused children MOSAC but it's staffed by volunteers and not open tonight.

[needadvicefast]

Have posted this in child mentla health so please reply there, thanks.