Not much is known about their personalities because they are not focused on a whole lot. They obviously enjoy the art of hula dancing, since they attend a hula class along with Mertle. While they are mostly mean towards Lilo and Stitch, they are also kind to them as well, usually when Mertle is not around at all, so it's hard to tell whether they are nice or mean hula girls. It is actually implied several times that they may actually hate Mertle and only hang out with her because they don't want her to bully them. Sadly though, this is never looked into, since they are minor characters. Of the three girls, Yuki has the most distinctive personality (albeit not by much), with her expressing an interest in ice hockey in a few episodes of Lilo & Stitch: The Series.
Role in the series
They usually travel in a group with their leader Mertle, and seldom say anything other than a sarcastic "Yeah!" in unison when agreeing with whatever mean thing Mertle has just said about Lilo. It is often hinted that the three hula girls would probably actually like Lilo if Mertle didn't make them think that they didn't. They have even ditched Mertle to hang out with Lilo for a while, like in the episodes "Tank" and "Shush", and they seemed to have enjoyed their time with Lilo on both occasions up until sadly going right back to Mertle in the end. Also in the episode "Mr. Stenchy", Elena says to Mertle, "Hey, there's Lilo! Should we invite her, too?", referring to one of their little tea parties at Mertle's house, and sounding as if she wouldn't mind having Lilo join them.