hehe, get your sister to buy a different brand from the one you buy, then you can try out both 
i can’t guarantee that you will love epilating any more though! if you can bear the pain, it’s so exciting in the beginning, until you get ingrown hairs of the like you could never imagine - really painful! BUT everyone is different, it works well on my arms and underarms, for others it works well everywhere, and for some it’s just horrible anywhere! 
good luck! it has to definitely be tried.