My Daughter Had A Small Dark Mole Removed From Her

My daughter had a small dark mole removed from her inner thigh about a year ago. It was removed because it rubbed against her running shorts and was sort of awkward. There was no sign of it being melanoma. however, she does live at a beach area and she reported to me today that the mole has grown back. Is this a definite sign of melanoma or do moles often grow back? The original mole was raised ever so slightly.