You poor thing, how scary and sad for you to hear. I would sincerely hope that any psychologist working in adoption would fully understand that children who have experienced trauma and neglect can process it in different ways, and one of those ways is to "re-live" or "re-tell" what happened as if it was happening now. It's also not unusual for children to make sure they get attention from adults around them in this way, especially if their previous life has been chaotic and adults have been unreliable, so the children have learned that they need to "spread their bets" and keep the attention of all the adults around them. It's utterly tragic, but it takes a long time to build security and trust, and find healthy ways for them to express their past experiences.
If this were happening to another family, it would be easier for you to remember that any professionals who have a disclosure like this made to them are obligated to report it, and to follow up on it, because in some of those cases they will be protecting the children from risk of serious harm. However, they are going to look at this in the context of what your children have previously known in their life, and as incredibly hard as it is, you need to trust them to do that and follow the process right now.
Am I right that if you're applying to the ASF, you already have your AO? If so, these are legally your children, you are their family. People are not going to swoop in and split you up, but I expect people will want to talk to you and perhaps keep a close eye for a little bit - if you are needing extra support (and you are early in placement really, with two children) then that close eye can become a really good thing because someone should hear what you are trying to say about your children's needs.
Take care of yourself and go very, very gently. I know this hurts and is frightening, but if you can, hold on to the fact that this is not about you, or your parenting, or even about how your child feels about you - this is about them expressing pain, caused before you even met them 