My son never could latch on but I pumped for 9 months, so I had to do a lot of research on increasing milk supply! Here are the tips:
***Beer, the darker the better, or you can use brewers yeast tablets. Brewers yeast is the active ingredient in beer that increases milk supply.
***Mother's milk tea, found in health food stores, or a Meijer if you have them. Loved this! Noticed a difference if I missed a day.
***Fenugreek herb.
***Blessed Thistle herb
*** You could pump at the times she doesn't seem to be getting enough, maybe after she goes to sleep. This will keep you body on schedule.
Can't remember the exact dosage on the herbs, but my pediatrician's nurse told me about them, so you may want to ask yours for the dosage. Or contact Le Leche League, they may know.
Hope this helps!
M.