Janice Dickinson tells TMZ, the mother who accused the ex-supermodel of attacking her outside an L.A. elementary school has the wrong person -- and the mistaken identity could derail her daughter's life.
TMZ broke the story ... Janice was sued by a Jill Gatsby -- coincidentally, the jilted niece of murdered Hollywood publicist Ronni Chasen -- who claims Janice smashed her in the face with a cell phone while she was waiting to pick her son up from school.
But Janice is adamant ... she wasn't the attacker in question -- in fact, the "Celebrity Rehab" alum claims she's never been anywhere near the school in the lawsuit ... and she wants to set the record straight.
Janice tells us, she's especially worried because her daughter is applying to colleges now -- and she doesn't want some bogus lawsuit tarnishing the girl's reputation ... sabotaging her chances at getting in.
Janice says she's considering filing a counter-suit for defamation. We called Jill for comment -- so far, no word back.