I think it's fair to be concerned, but I'd give her the benefit of the doubt. A friend of mine has a kiddo, and while we don't hang out as often as we used to, she still joins me in tearing up a dance floor when she can. If she DOES drop off the face of the earth, by all means, that sucks, and you can have a convo with her about it if you feel it would help, but in the meantime, maybe wait and see if she actually falls into that category? I hope she surprises you!