SAHM to two boys & a girl. DS1 has eczema, asthma & is allergic to: dairy, eggs, peanuts, shellfish, seafood, sunflower, yeast & garlic.
im not sure where you live, but in canada we have these AMAZING probiotic drops made specially for children/babies they are called biogaia probiotics and they are in a small glass bottle, kept refrigerated at the health food store pr natural pharmacy. i highly recomend them. you need like 3-5 drops and i would just drop it right into my babies mouth while i was playing with her or changing her. i use them on and off now, but when she was tiny she had serious projectile vomiting issues and they cleared up almost immediately with these. my midwife suggested them.
If probiotic powder mixed into food or on your nipple doesn't work, you could make a little paste and swab it on the inside of her cheek. That would reduce contact with some of the more taste-sensitive parts of her tongue.
Good luck! :-)