Do you like the girl and you would want to be more than friends? Are you using this as the ice breaker (my assumption is yes if you are using the King of Hearts lol)...or do you want to go just as friends? Have you talked about prom nonchalantly to see if she's interested in even going..has SHE dropped any hints? For most girls, prom is a huge fucking deal...but some just think of it as an event...know your battle and set realistic expectations of how to confront it.
If you do infact have feelings for her, try to at least find out if they are mutual back (ask around...her friends / mutual acquaintances you can trust). The last thing you want to do is get rejected and have this totally backfire. This could also ruin your friendship, as girls are notorious for becoming uncomfortable around guys that they know like them and don't like them back.
^^That exact scenario happened to me when i was a junior and my heart was fucking broken. I lost a great friend...she still talked to me but not like before. It was horribly awkward from here on out. I spent the better half of that year listening to terrible emo music as well. All in all a 1/10 experience.
Now if she does like you back...then it's a pretty cool thing to do, and you'll probably get brownie points for going out of your way doing something unique like this.
If you just want to go as friends, then just straight up ask her to go AS FRIENDS with no shenanigans.