Complex sentence: She goes to visit Collete in the hose where she lived with Tracy and Collete opens the door she doesn't recognise Carol, she asks what Carol is doing there she explains that she has come to visit old friends.
Split into simpler sentences: She goes to visit Collete in the house where she lived with Tracy, but she doesn't recognise Carol. She asks what Carol is doing there she explains that she has come to visit old friends.