M.H.
Things that could be causing it.
Milk _ususally a daily consumption
Gluten - also a daily consumption
Possible food Dyes- in things people eat regularly.
Eggs- in things we eat daily
Soy- also in things we eat daily.
I would have her tested.. Take things out for a few weeks and then intruduce them back and see what happens.
Has you Dr offered any kind of testing to see?
Good Luck