Parents should be more concerned about the EFFICIENCY of their DD's pitching. PROVIDED she's playing a top notch ASA summer schedule, what is her ERA? Does she get a lot of routine ground outs? Nice easy pop-ups? Does she routinely get behind in the count? Is she throwing 12 pitches an inning, or more than 15? Does she get a lot of line drives hit back at her, or up the middle? Face it - four 65 mph pitches that the batter doesn't swing at, and are off the plate are a WALK in any softball game.
These details are FAR more important in the long run. All things being equal (mechanics), top pitching speed - like running speed is governed by genetics. Rarely will you see a dramatic increase in speed from 16u to 18u. BUT - the BIG difference is accuracy, endurance and all the little things. Learning to pitch to a batter's weaknesses will take her a LONG way. Don't embarass your DD come college recruiting time. The more you brag on her speed, the more she's forced to live up to that - and MOST don't. Be proud of her accomplishments for what they are, and don't get caught up in the bluffing game. The best ones go about their business silently and let their performance speak for itself.