Hi LasswadeCoach
I am male. I really appreciate you saying that. Sorry it has taken a while to reply, i started work again (Coaching) after having been on surgery recovery leave for a bit, so it has been hard to find the time to reply.
The reason why i know about this, i guess
1. I make it my buisness haha
2. I do have a degree in Health and Science with major in Exercise Science, and i guess more on a biomechanics side rather then physiology (but by no mean a biomechanics of any kind). So that helps.
3. I read a lot on this sort of stuff as well, in research and stuff for writing artcile for The Gym Press
I am glad i can help, and i hope this information is helpfull to someone.
Tumblequeensmom you are onto it. The situation is very common and i would say about 90% of gyms (from my exeperience) don't really work on stretching the hip flexors (that includes the quadriceps, Rectus Femoris, and to some degree the Vastus Intermedialis muscles in particular) separatelly. Generaly speaking the hip flexors are conditioned to be STRONG rather then flexible. If your daughter is really serious about improving her squareness Do try and get your daughter to do the exercise i recommeded for 4 weeks, 4-5times a week, for 3x30sec per leg with 20sec rest between sets (if she has time and the training attitude try to do 3x1min by the fourth week, so increase the time by about 10 sec or so each week). I am confident that as long as she really works hard at it and focuses on trying to hold a square split rather then just to do any split she will achieve great results by the end of the 4 weeks. When she stretches she should always be trying to push herslef to the point of absolute pain threshold. This means she should be able to tolerate the pain but unfortunately it will/has to hurt (this is because flexibility improvements (passive in particular) is a result of improved pain tolerance)
There is however 1 point to mention and that is that perfect squareness is not achieveable by everyone, due to variations in morphology. But very good results are achieveable by virtually all kids.