Why is this girl ignoring me on facebook?

[Kaede]

First off, THIS HAS NOTHING TO DO WITH RELATIONSHIPS AND LOVE.
So theres this girl in my physics class and we barely ever talk. The only time we talk is like in the morning when we pass by, were all like"hey there", then we walk away. sometimes we have really small convos. So like i needed the homework page number since i didnt write it down in class, so i msg her, no response, a 2nd time, no response. Then i look to the right and i clearly see that shes active, commenting on photos and liking stuff. I'm then forced to go on her page and ask her. Shes 16 btw
Maybe she doesnt know the page number, but thats not the point. The point is why is she ignoring me?
Are you serious? Bothering her? I only msged her 2 times and posted something on her wall.
Don't have to do with facebook? She's ignoring me on FB but not IRL. Wow, so far all the answerers are total assholes.
And shes not busy busy, shes busy liking memes and commenting on photos of her friends