When DD2 had her 2 week check i bawled to the health nurse saying she only feeds for 5-10 mins and only ever from one side, i was so worried she wasnt getting enough, but the nurse said they like to see a weight gain of 120-200gms a week, and going by that rule, your bub is only just just just under that, so i think you're doing perfectly!!
like the others have said if she's happy and settled(as happy and settled as a newborn can be!) not lethargic, plenty of wet nappies ect, then you're doing just fine.
Some babies are just slower at gaining weight than others, DD2 certainly was but even though her weight gains were small she still followed her own pattern on the graph that they use