Is Iron Deficiency Related With Body Pain, Dark Eye Spots And Stomach Upset?

My daughter has been experiencing pain all over her body. her eyes have dark spots around for a while now. She has to take sleeping pills to be able to sleep. She also takes Sertraline for depression. Her tummy gets upsets so easily. She does not take any meat products anymore. She eats mostly fruits and vegetables as well as cereal and dried nuts. She thinks that she has gluten allergy and fibromyolgia. Do you think she has iron deficiency? Thanks. Connie