My 10 week old I think just went through a growth spurt where she was taking much more milk than usual - going from 2 ounces to 3,4,5. She is small but doing well according to HV's (9 pounds) so she should be taking the larger amounts. If it was a spurt, it lasted about a week, and she wasn't feeding more, but taking in more amounts less frequently - which was great!
But in the past few days she has gone back to 2 ounces again. She is also falling asleep immediately after feeds in the day (usually only does that at night). We use MAM bottles. Does it sound like she needs a faster teat? She's not taking a while to finish the milk, but sometimes I'll pull the teat out and she may have chewed it down.