Confused as to what to do with BYB pup parents bought? Aggression or play?

Being left with her litter mates for an extra three weeks she has probably developed some dominant tendencies. You will have to work extra hard with training. Putting her in her crate for time out will not help her to learn. Don't allow her to do anything that you don't want her to do as an adult. Make sure she gets a lot of leash training several times a day. Take her to obedience cles as this will help teach you how to train her.