Hi Beth -
The only suggestion I can make is to check with the people at the Sabino Canyon visitor center. There are several trails heading out from the center, they utilize a shuttle system, and it has always been crowded when I've been there, so I would think they would at the least be able to tell you when group hikes are planned. Another option might be to check with the store The Summitt Hut. They might be able to put you in touch with somone.
hope this helps
'The Journey is the Destination!'