She suddenly stopped responding to my texts, but she's into me

Theres this girl I met at school which obviously is into me; she always says "hi" to me every time she sees me even if I'm far away, she notices me... Show More

Updates:
PS

this spontaneous text avoiding behavior I'm seeing with this girl is something I have seen with other women I have got numbers from. This isn't the first time this has happened to me. It seems to be some kind of pattern. The girl will unambiguously be showing signs of interest, we will have a nice text conversations, but when I go on to ask her out on a date, that's when they spontaneously stop responding to my text. I can't come up with an explanation that makes sense. help!
PPS

The instance I discuss where she suddenly stops responding to my texts after being asked out is actually the second time I asked her out. I had actually asked her out once before, but she wasn't available on my schedule in that case..forgot to mention this.