D.Z.
Hi Y.,
I don't think it is a coincidence that there is a new baby and your toddler is hitting. It must be hard to share mommy with a baby, and even though the behavior started before the baby was born, there are definite changes for her even before the baby is born. I would try to spend some special time with her (not easy with a new baby in the house) but maybe your husband can take care of the baby for an hour or so to allow you to give your daughter your undivided attention. This might help, or I could be completely off base, but it is a possiblity. Let us know what happens.
D.