my dd was much younger, but struggled for awhile after ds was born. she got quite violent, and we couldn't leave her with the baby unless there was an adult in arm's reach.

we found her behaviour improved and she was much happier, when we planned more one on one opportunities, especially physical ones. (park, wrestling, trampoline, big cuddles or tickles).

we also made opportunities for short, positive interactions between her and baby. it made her feel important as a big sister.

now they are great friends , but I wondered if ds would even survive his first year, in the early days.