Why didn't you ask her directly,

what was making her bring up the subject of AS adult support groups to you? I sure would ask while looking straight in her eyes, and if she tries to avoid the answer, ask again. Should be fun watching her response.

If she was indeed experienced being around AS adults, there must be some commonalities she could recognize - peculiar gait, gaze, movements, facial expressions (or lack of such), etc. Another two common features i personally noticed in several AS women (myself and a few those with whom we exchanged photos over the Net), are: hair always pulled back (in a braid or a ponytail) AND large glasses of rather old-fashioned style (i can't stand modern small frames).