What is the appropriate age to educate young girls about periods?

We have been advised here in Australia recently to talk with young girls of about 7-8 early and often to help them develop a healthy understanding of their bodies and to prepare them for the big changes puberty brings. Certainly girls need ownership over their bodies and an open dialogue with their families; this helps prevent sexual assault as they are more likely to stand up and tell someone if this happens to them. Girls are menstruating earlier each decade, although about 12 is the average. Some girls with precocious puberty may menstruate as early as 6, although hormone therapy can suppress this if it is deemed socially detrimental. Keep an eye on your young girls with view to educating them at the right time about this - their breast buds will start to develop roughly one year before the onset of periods. Other subtle changes such as pimples and mood swings may occur, and certainly pubic hair will start to sprout. It is far less frightening for young girls to be educated about these changes than for them to suddenly wake up one day thinking they are abnormal or are bleeding to death. There is no evidence that educating girls in this way leads to early sexual experience. In fact, the more knowledgeable and in control of their bodies they feel, the more likely they are to stand up for their rights, develop good self-esteem, and a healthy relationship with their bodies.

In my opinion the instruction is must giving at the age 10 because many of the students are do not know correct information about the periods.Many resources and books are providing the clear information through simple language.