16 month old biting and pushing!

[littlefrenchonion]

My 16mo DD has spent the day with my SIL and their 12mo DS while I did a rare Saturday shift at work. Apparently she's been an angel the entire time.

Not since I got there - she's bitten her cousin 3 times causing a bruise (he was after her toy, or in her space, or trying to get in the ball pool with her). She's also been slapping him away if he gets too close, and she's pushed him over a few times.

This is the first time I've seen her behave like this - I'm at a bit of a loss with how to deal with it! I've been pulling her aside and saying firmly and sternly "No! We do not bite/hit/push!".

Any tips?