The IRS says they have to be a full time student for five months of the year, is that five full months or parts of five months?

Also, after she graduated she lived with her parents, used their health insurance,  lodging etc. she did buy her own car. she made $30k during the year.  It is my understanding that it doesnt matter how much she made as long as she provided less than 50% of her own support.  The parents want to claim her on their taxes to get the tuition and student loan interest deduction. Please provide direction.