Dependent

It does seem we will be able to claim my 25 year old step-daughter as a dependent.  My question is this?  How does that affect her tax filing status?  She is a college student going to school on the GI bill and only grossed about $3,000 this past year.  Will she still get all her federal taxes withheld back as a refund?  She will not be able to claim herself when filing if we claim her, correct?