OP - this is PP. Be patient with regards to stixrud tutors replying back to you. it can take awhile. That said, I would keep searching as it can be difficult to find a tutor mid-year. Many are fully booked by the end of Sept.
I would also call the person who runs the tutoring program at Stixrud for her input. She is very knowledgeable and used to work at the McLean School. she can help with regards to which tutors are best suited for your DD.
Also try Ann Dolin's website, she is an educational consultant in NoVa but her tutors are everywhere. she is also very knowledgeable.
http://ectutoring.com/