im confused about the reasoning. nursing on demand will provide your daughter with the proper amount of nutrition. pumping is not as efficient as her, therefore will actually lessen your milk supply where she would increase it. are you keeping track of her wet diapers? that is how to monitor her intake. if you want to be super technical, you get a very good scale, and weigh the wet diaper and subtract the wieght of an empty diaper. that is how they monitor BF babies intake in the hospital.
why do you want her to gain more weight? is this the doctors recommendation? is you doctor an advocate of breastfeeding? if she is low in her percents, thats perfectly fine. its only of a concern if she dramatically and consistantly is going down on her charts. if she has always been in the 3%, and still is in the 3%, its fine.
my daughter has always just eaten 10 minutes. actually when she was 3 months, she ate 5 or 10 and thats it. the amount of time she nurses is NOT an indicator of whether she is eating enough or not.
get a nursing necklace to keep her attention. continue with the white noise while feeding her. in the middle of the night, try to feed her in her sleepyness. feed her more often. please do NOT feed her formula. do NOT feed her solids. do NOT stop breastfeeding. do NOT get caught up in how much she eats. that is what bottle fed babies do, not breastfed. the wet diapers and how often they eat are the indicators. do your research on breastfeeding. dont let anyone confuse with the whole "are you sure the baby is getting enough". your breastmilk is more digestable and nutritious than anything else.
please forgive me if she has some medical issue. these thoughts are based on my assumption she is medically ok, and you are just worried about the "how much is she getting". if you talk to the wrong doctor, they give incorrect advice and i just wouldnt want anyone misinforming you. here is the american academy of family pediatrics position on breastfeeding and how important it is.
http://www.aafp.org/online/en/home/policy/policies/b/brea...
here are some great articals including a section on baby weight gain concerns http://www.kellymom.com/bf/index.html
lalecheleague FAQs http://www.llli.org/FAQ/FAQSubject.html?m=0,0,3
there are tons more but maybe some of your concerns will be answered on these sites. fyi, my aunt had 3 kids, all EBF. the first 2 were average size children, not small but not super big, average to a little bigger. her 3rd was so tiny, 1% on the growth chart. she was just the tinyest little thing. now at 4, she is the size of my daughter who is 10 months younger. but she is completely healthy, just petite. on the other hand my niece who was a pretty chubby baby, is now 9 and measures the size of a 6 yr old. now that is concern. at 3 months old as long as she is gaining, i wouldnt worry so much.
again, i assume there is nothing medically wrong.