I want to ask her out but I'm not sure if she likes me?

I met this girl because I noticed she was sitting outside my classroom and started greeting me though I didn't know her and had never seen her before, that was in December of last year. We had our vacation and the thing continued in the same way. Sometimes before class she was outside my classroom with a friend, while doing her stuff so she couldn't be aware of me so her friend told her something and she turned around and said hello to me, that happened twice. So after some time, I found her on facebook and sent her a friend request which she accepted. One week later she liked my profile picture that I had changed in January, she accepted me on Facebook on the last week of February and also commented with a smiley face and that was on March. One day I decided to send her a message through facebook and we talked, until she saw my message and didn't reply and one week later I send her a message again and we talked for some time until she left me on seen again and it happened like that every time I sent her a message. So one day I went to school earlier and she was there and I said hello to her and was about to leave because I was a quite busy and she told me "First time I see you get here early" and we talked about 10 minutes. Then I wanted to ask her out but I couldn't because we had gone on vacation for two weeks and decided to send her a message again and ask her for her number, but she took hours to reply to my message when she always had replied to my message instantly, and when and I ask her if there was no problem she gave me her number, she said " it's no bother" so after that I replied to her and did a little joke about her taking too long to reply and asked her about her number: is that a yes or a no? Well, that was one month ago, I stopped sending her messages for 3 weeks but in Saturday I sent her a message and we talked for certain time. What should I do? I don't know if it's a good idea to ask her out because I'm not sure if she feels the sime as I do.
I want to ask her out but I'm not sure if she likes me?
Add Opinion