There is an excellent article about starting pointe written by the International Association for Dance Medicine and Science (sorry if someone else has already mentioned this). I really think it is well worth having a read, they have some excellent articles on a range of related topics too. I appreciate that teachers and parents will use their experience and best judgement to decide when a child should start but their experience is always going to be limited to just the children they have seen. Those children may not necessarily be a representative sample. Here is the link http://www.iadms.org/?185
I've copied their summarised suggestions here;
To summarize the above discussion we offer the following guidelines for when to begin pointe training:
Not before age 12.
If the student is not anatomically sound (e.g., insufficient ankle and foot plantar flexion range of motion; poor lower extremity alignment), do not allow pointe work. If she is not truly pre-professional, discourage pointe training. If she has weak trunk and pelvic ("core") muscles or weak legs, delay pointe work (and consider implementing a strengthening program). If the student is hypermobile in the feet and ankles, delay pointe work (and consider implementing a strengthening program). If ballet classes are only once a week, discourage pointe training. If ballet classes are twice a week, and none of the above applies, begin in the fourth year of training.
