dude how old are you?! That's what you see in the movies and a middle schooler does that where the girl has to circle yes or no. at your age, girls will just get a clue solely if you just talk to her in a normal way and if there is chemistry via chatting online, then you can start to flirt and then if she reacts in a positive way, keep it going for a little while to keep her interested and wanting to talk to you. Later just ask her out for coffee or something small to hang out. Being blunt will scare her away
Don't ask her if she likes you. That's so lame! Tell her you think she's amazing and that you'd like to take her out. If you've already gone out, then tell her you can't stand the idea of sharing her and you need things to be exclusive between you two. Women like a confident man that can take charge. So instead of asking her about her feelings, tell her about yours. You'll know right away how she feels by her reaction.