K.F.
I've seen Grace Avenue United Methodist Church in Frisco off Main St. next to the YMCA. They have a preschool called Rainbow Corner but it looks like they're full for the year and the wait list is closed. Maybe you could try a service there to see if you like it, you never know a spot in the preschool could open up during the year.
http://www.graceavenue.org/index.aspx