While I understand you are a "small group" rather than a guild, all I can think of is the many threads there have been about guilds that are unfriendly or unwelcoming. Not sure how your group is any different?
Unless this woman doesn't get social cues (there are many with disabilities who don't), my guess is that she won't be back, or at least not more than once or twice. I sure wouldn't return, and am grateful that the guild I belong to is more welcoming.
Groups that are exclusive are sure to dwindle - whether through illness, busy-ness, loss of interest or passing of members. Without new folks joining, there's only one inevitable outcome.