It very well could. HOWEVER, it could go the other way also.
No-one knows for sure. I'll tell you the same thing I tell my wife when she is feeling ignored by her boyfriend; Let it ride and wait for the fall out....or the build up.
You see, she could have been too busy to shoot off an e-mail this morning. You said "usually", which implies that she doesn't ALWAYS e-mail in the mornings. Be patient, and be confident that if she truly IS a "friend", then she will accept you for who and what you are....No matter what. And it could POSSIBLY move to more than just "friends".
I know this doesn't help much, but please try to be patient and look for the best first.....Instead of the other way around.