Can the donor in breast augmentation with fat tranfer be a relative?

If i don't have enough fat for the procedure, can my sister, who definitely has, ve the donor? Will that affect the cost? I'm a defltated B-cup, due to yoyo dieting (which i have stopped and now i maintain a healthy weight) and i'd like a full C-cup, or as close to D cup as possible. My main fat storagr is in my thighs but i do not believe the fat in my body is enough to achieve the change i want. Also, i like the rest of my body and wish to change nothing about it.