Do not know where to find clip ons but if you can find disney themed regular ones you could turn them into magnetic earrings. All you need to do is buy a pkg. of replacement magentic backs from a jewelry store and either super glue or solder them onto the regular earrings. DH has solderig tools for the computer so just ask any tech geek for assistance if you do not have the equipment
I have done this for both DD's with earrings they just HAD to have. We are waiting until the girls are 13 before they can get real holes. DD9 thinks getting pierced is the equivalant of torture where as DD8 considers it torture having to wait for the privledge... I can never win!