My DD started waking about twice a night at that age too. don't really know why but b/feeding put her back to sleep quickly so that is what we did. It probably lasted about 2 months but I can't remember noticing she was any less hungry during the day.
by the way, DD is 4 and still sleeps in our room. there are only 3 of us in the house and we don't see why 2 of us should be in one room and the other in a room on her own so we sleep together. Now if there were 4 of us it would probably be a different situation.