I'm going back to work very soon and my 11.5 month old DD still won't drink milk out of anything but a breast. We've tried formula and expressed, bottle and sippy cup. She'll happily drink water from the same sippy cups she refuses milk from. We'll try her with cow's milk when she gets past a year but if she refuses that too, will she be OK not having milk while I'm out of the house? I'll be out roughly ten hours a day, four days a week.