One of my "friends" left her 13 year old and 10 year old with me to go back to an abusive relationship. She did not call or even text to see how her kids are and is just now telling me she wants me to take her 13 year old to her and I can keep her 10 year old. What can I do to keep both of the children? I just want them safe.

First, you have no legal right to the children at this point. You can't legally authorize medical care or register them for school. So you need to get an attorney and file immediately for temporary guardianship.

Once that is done, you can then investigate gaining custody, though that is a long shot.