Hello and welcome! I have nothing to say about potty training, since my bird is about 15 years old and still goes where he wants. However, in my experience, greys usually have a "favored" person (which may change over time). As for others, they do seem to have definite preferences and dislikes. Even so, they will usually develop some sort of relationship with everyone in the household they have regular exposure to. If your daughter keeps working on it and builds trust, their relationship will probably improve with time. The short answer is, yes they do have definite preferences and likes and dislikes with individuals.