What's the best way to....?

There's this girl that I met at this course which we both went to. I sort of got the feeling she was into me, and I was into her. Nothing happened, and we never really hung out outside of the course. The course finished a while back and we haven't seen each other since. We did text a little, but haven't texted since. The question is, if I text her, what could I say? Is it a little weird to just text someone like that after a number of months to just ask how theyr'e doing?