I don't know what to do but I want her?

Ok. I been friend with this girl for 3 years. Today she send me a long text saying she hv a crush on me since the beginning of our friendship. She expressed her feelings and said she dont expect me to feel the same way. She's cute, beautiful and I like her. I really care bout her so much. This is part of what she said "I been having this feelings for ages it's nothing new. I feel embarrassed to tell you this, I had soo many dreams bout you and it was soo random" my question is what should I do? Or what should I tell her?