Does she drink a lot of tea/coffee?
Caffeine intake with food limits the absorption of iron into the blood stream. While in most people this is inconsequential, for those who do long distance running (something to do with impacting the joints), so ensuring correct iron uptake is important.
I read a research paper many months ago but the conclusions were no caffeine 60 minutes before food and none 120 mins after food.
scholar.google.com might help you find some research on this.
Hmm...I shall have to inform her of this I had no idea!