Not much is known about May before Pokemon, except that she seems to be related to Max. Her father is believed to be a gym leader, but he stinks, and people beat him without trying, because he only uses that sloth Pokemon.
Because of this 'important' position, May became accepted into the show.
May is the hottest girl in Pokemon , tied with Dawn beated Misty. She would be hottest, in front of Dawn, but for some bizarre reason, she grows the sides of her hair long and shaves the rest of her head (not to the point of baldness, but enough to be noticed).