I breastfeed my 14-week old, and she takes bottles of expressed breastmilk while I am at work. So far she has not had any issues switching back and forth from breast to bottle. I alternate breasts, and she usually eats for 20-30 minutes at a time. I'll offer the other breast, but she usually falls asleep and is uninterested. For the past few weeks she's been content with 4.5-5 ounces at a time when bottle-fed. This week she's been asking for more, one day she took 6 ounces, and another day she took 8! I know that there are growth spurts, and maybe this is one.. but I'm wondering how much expressed milk other babies her age are taking at a time. She's about 13 pounds. I keep reading on KellyMom and other websites that breastfed babies aren't really supposed to increase their milk intake between 1-6 months because their rate of growth slows, but that doesn't seem to be the case for my girl!