I've had this person booked for a while now and I am expecting her on Thursday so I send a "looking forward to meeting you" text to find out it isn't her that is showing up but her 2 friends.
Am I wrong for feeling a little uneasy about this visit?
I'm assuming you already asked for who are her friends and the reason why they couldn't book for themselves? If you feel uncomfortable, contact Airbnb and see if they can verify her friends on the backend. It's worth a shot. Maybe have a friend with you during check-in.
I've had people book on behalf of others before but every time they told me in advance. The reason was usually either because they were booking for their parents or their friends who don't have very good English. In one instance they even had the other couple message me with a "bio" before booking.
I think not telling you in advance is a big no-no and if you don't feel comfortable you should let airbnb know to fix it for you.