They definitely will have met, and will likely know each other well, at least superficially.
Their relationship will depend largely on Thais' reaction to her. Ashya acts mostly the same to all Circle mages - she will learn as much as she can from them, but will test their limits to see how much she can push them, and what they will let her get away with.
If Thais has her finger on events within the tower, Ashya would have tried to get to know her - basically, all gossip is good to know. Being nosy, she tends to get around where she shouldn't, but being quite young, she doesn't really read as much as she should into people's words and actions, so she probably wouldn't have much news to offer Thais in return.