Tounge tie???

Andrea
So my new baby girl is 11 days old.. was born at 37 weeks 7.5... she has lost weight and went to 6.10 but since only went up one oz. Im reading and really wondering now if this is the cause.. it seems when she nurses its never a full feeding like she pops off a lot and only wants to nurse for a short period like 10 15 min or so fall asleep then eat again im just hoping to get it figured out so she gains.. does anyone know how else to tell