<human>: Can you succinctly summarize the text in 1-3 sentences?

Hello guys.

I was taking a course in university and one of my classmates was this amazing looking lady. I started flirting with her and received giggles from her and her friend. Half way through the semester I got her number and started texting with her. I asked her out about a week after that (end of March) and she refused saying that she is talking to someone. 

Since the semester still continued I kept texting her (the possibility of dating her was out of the picture since she was dating someone and I am not an asshole). Over our texting conversations, she replied with short answers and never kept the conversation going (closed answers and no reply questions).

At the end of the course (May 9th), we said out farewells, and I honestly didn't expect to hear from her again.

FF to June 15th SHE texts me and a conversation started, but again, she replied with short answers and never kept the conversation going. I stopped texting her because I forgot.

Today, she texts me again asking how I am doing.

Can someone hypothesize what the heck is going on here? What am I looking at? What is my response to this behavior?

This kind of behavior is not something I am familiar with and I haven't read anything like it here in this sub.

On a different note:
I wanted to thank you guys for your help with people's problems here. You helped me a lot with my problems by helping others that are going through the same troubles.
<bot>: Former classmate, I asked her out, she said she is talking to someone. Kept texting with her as part of the class. She started texting me again a month after the class ended, and again today.