You could give her half before you go and half when you get home. I've done things like that. Even though you need to be at the dinner at 4 pm, it might be served later than that, maybe not until 5 if there are any appetizers or visiting to be done before the meal, then you don't want to eat and run. So, I've done the half and half meal before and it hasn't been a problem bathroom wise. I feed the first half early enough for a bathroom outing before I leave and feed the second half as soon as I get home. I don't know if the dogs care (sure they do, at 5 pm they let me know it's time to eat) but it makes me feel better.