Why Won't She Follow Me On Twitter?

Firstly, I just want to make it clear that at the end of the day it's just Twitter- I'm just curious and thinking that perhaps I'm missing something obvious... you tell me.

There is a girl I've known for about 2 years now, and we talk a lot (texting more than in person but that's a different story) and about a month and a half ago I professed my love for her. I'm 16, so most won't believe that I love a girl at this age, but the fact is I absolutely adore every little thing about her and love everything about her, so love is the best word I got. Anyways, I'm following her on Twitter (for obvious reasons) and I've favouited a few of her tweets, replied to some, and retweeted some, but she doesn't follow me. I'm just curious as to why she won't follow me. I don't spam, she said that she's ok with what I told her (ie. things aren't awkward between us) and I'm always friendly on Twitter.

Like I said, it's really not that big of a deal, but is there any reason why she isn't following me? Thanks :)