how to handle uncomfortable situations with other parents.

Obsession

My son's therapies are at our local children's hospital and now that we've been going a few weeks, we are starting to recognize the faces of the other patients and their parents but I haven't made small talk with any of them yet.

Today we were in the little play area after our appointment and a little girl was talking to me.  Her mom came over with maybe 3 seconds of small talk asked why we were there.  I just smiled and said therapies.  She then started volunteering a ton of info about her son and all the things that they were dealing with.  Is that normal?  I'm not comfortable with that.

Thankfully my son decided at that moment he wanted something so we said goodbye and  left but how do I handle in the future?