I came
across quite a bit throughout life and really, unless you can see
through than just blind love, its almost impossible to realise if
she is only being herself or is there truely something more to it.
I can't teach you to look beyond blind love because it can't be
taught, but eventually you will understand how does this game of
love works.
I have two suggested advice:
I) You feel that you could no longer store your feelings in your
junkroom of emotions. It is bursting as if someone on the other
side is ramming against it. If you want to tell, you have to date
her out somewhere real good and probably express it out.

- Before you decide to tell her, please do not attempt avoidance or
weirdo+ness tactics aftermath. To express is simply to tell, there
shouldn't be any condition attached to it. If you can't accept
this: avoid expressing, yet.
- To express is simply to tell (x2 stress); therefore be calm,
stable and speak as if you both were 'sisters' - anything under the
sun could be exchange in verbal form. Laugh, smile and accept if
things doesn't go your way. I know it could be disappointing if she
doesn't accept your proposal, but on the other hand, isn't
revealing how you feel a great relieve off your chest and that is
the objective of your move?
II) Keep mum. Until the day when she tells you she likes you,
before you reveal that. (This is great risk).
Astro mode: If her astrological signs falls under Leo, Sagi, Aries,
Gemini, Libra or Aquarius - you can consider (I). If other signs -
can consider (II).
P.S: At the end of the day: Listen to yourself. 
Cheers