There is a lot involved with finding the "right" pitching coach for your daughter. This question gets asked every so often, and the same 5 or 6 instructor's names will again appear. There is no doubt that these instructors are very knowledgeable about pitching. What you, as a parent along with your daughter, have to do is find the coach that 1) you and your daughter are comfortable working with 2) communicates well with your daughter using language she understands 3) Demonstrates proper technique in a way your daughter understands. Regardless of how good folks say someone is, they are only as good as you and your daughter perceives them to be. Your daughter might get nothing out of a coach that is just loved by someone else. In other words, to each his own!
Other factors of course are how far you want to take this - do you just want a few lessons to help her get through the summer, or does she have a burning desire to be a college pitcher some day? This is an important consideration, because some coaches will not waste their time with a "part-time student". Face it - pitching is a very difficult craft, and requires a LOT of hard work and dedication. You have to decide what you are after. There is no right or wrong, but rather finding what suits you, your daughter, and your budget for time and money.
I would strongly urge you to go take a lesson or two from each of these coaches. Don't get "wowed" by the first one you go to - you just might pass up a better fit. As a parent, I would also strongly urge you to educate yourself on advanced pitching mechanics, strategy, etc. You yourself don't have to be able to throw those pitches, but at least you should know what they look like, and know what good pitching form is. Especially at a young age, a parent is a very important part of the formula for success. Too much pushing can cause burnout, but not enough will not allow her to develop into all she can be. It's a fine balance that only a parent can manage.