Do kids pick up habits from other kids? My daughter has a regular play date with 2 boys in my condo and they are always pushing and biting, and throwing tantrums. Will my daughter pick this up, or is she more likely to behave based on how she's brought up at home?

Yes, children learn from each other. You could explain to her that her playmates behaviours are unacceptable and highlight that she shouldn’t feel pressured to imitate their behaviour. The way she is brought up will help her understand and accept your explanation. You will still have to impress upon her that she has to learn to differentiate for herself what are appropriate and inappropriate behaviours. Children have to learn to decide for themselves how to resist peer pressure. In my opinion, this would be a good learning opportunity for her.