I can't give you an exact answer but keeping everyone's mood high isn't a probem later in the game. For the cow girls it might just be finding the right number of days per week to spend on the farm, or maybe they like being milked so much? Invest in those apples of power you can get from Basket for more energy per day, I'm up to 6 now which leaves plenty of energy for everything. So don't worry about it for now.