M.S.
while persuing what is ingested why not just try to wipe her mouth out with a wet wash cloth, especially her tongue several times. My boys (pre schol and infant) both get formula and milk build up on their tongues and nothing gets it clean like a wet washcloth and several swipes of the tongue rinsing it off each time. It makes a difference, better than toothbrush and tongue wiper. It is an easy immediate solution while persuing the other things. Good luck!