Relaxer/blow-out kit, biracial daughters hair is all natural right now...need help to tame it?

my daughter is biracial (caucasian/african american) 12 yrs old and her hair is all natural and thick, curly, dry, and long. she refuses to keep any type of grease in it. can't stand grease in her hair, oil sheen nothing...washes her hair everyday also. it is totally unmanageable and can't even get a comb through it. i thought relaxing it again would help. hubby suggests a blowout kit, not sure what that is or what the difference is. getting her hair straightened is out of the question-doesn't stay straight and too much money to maintain. THOUGHTS??????