In my many years of Fostering and adopting I have learned a lot. One thing I have learned is that ALL kids are curious about where that came from. No matter the age they are when you adopt them or how long they have been in your home, when they become teens they start asking questions and start looking for answers.
With Social Media so readily available today (which Im pretty sure came from the pit of Hell). It makes it all the more tempting and all the more easy for them to make contact. Some time this can be healthy and a lot of times not so healthy. This usually starts around the time they reach their teen years. Sometimes this can be just simple contact on Facebook to all out mutiny. The mutiny is usually them telling you that you are not their parents they don't have to mind you and usually a few expletive words mixed in. Sometimes the police may even be involved.
Now due to my lack of planning and lack of foresight I have been generously blessed with 6 teenagers in the home at the same time. Four of those are teen girls (so double the drama). I have several feeling the need to make contact with bio family. This is usually very threatening to adoptive families.
My advice on this subject is that it is what it is. You can not change their past no matter how much you want to take away the trauma they have endured. This is all a natural desire to know where you came from and there is no changing that. It is best to support them in their search and let them know they are loved and that they always have a place to call home. Don't ask yourself if you should let them see them or make contact. It is best to help them through this process and be there for support.
We often hear when we become foster parents that it is not about us. It is about the kids. Well this is one more time it is not about us.