A girl who calls herself a princess but is nowhere near qualified to do so. A Mexican Princess is a girl who is on welfare, and/or has a bunch of illegitimate children, and/or works in fast food and/or is fat and/or ugly, yet still calls herself a princess.
A real princess is beautiful, sexy, intelligent, and men worship her. She doesn't have to do anything because she's perfect and her man/men pay her bills and take care of her very well.
A Mexican Princess tries, and wishes to be a real princess, but she will never add up.
That stupid, ghetto girl Janel keeps calling herself a princess, but the fat retard works at a fast food restaurant frying chicken and lives off welfare, and has 3 kids by 3 different men. She's no princess - just a Mexican Princess.