My Pediatrician told me to introduce rice cereal ONLY at around four months, then start veggies at six months, fruits at eight months, and meats and corn at one year. That worked really well with my two children.
My guess is, your daughter's digestive system is still too delicate for those kinds of foods, especially meats. She's only six months old, so my recommendation is to cut back to just rice cereal, and veggies like peas, carrots, green beans, and sweet potatoes. Remember, though - introduce ONE veggie at a time, for about a week, to see if she has an allergy or reaction. If a week goes by and she does okay, then introduce another veggie.
Just don't rush it. She'll have the rest of her life to eat meats and heavier foods.
Take care and God bless!!!!