I think she had a lively personality and might have been wound up after just arriving back home after weeks away, mom just left for a weekend away, they had a babysitter one night and then a birthday party the next day, dad is on his own with the kids after a long time of "batch'ing it" (living as a batchelor).
While I don't know if this is a fact, I can easily imagine difficulties at the dinner table. Absolutely no excuse for violence, of course, but I am starting to wonder if he lost his patience with one of the girls at dinner time (and thus his statement he wishes the girls were home so he could tell them to finish their dinner).
jmopinion at the moment, subject to change, might not match others' opinions.