This is related, although not entirely analogous, to child beauty pageants in the West where children are hypersexualised. The similarity is that in both cases, pre-pubescent girls are encouraged and rewarded for behaving like adult women. I guess the difference is that a beauty pageant is unabashedly about physical appearance, while the classical dance is primarily about mastering a set of skills. It so happens that some of those skills require the adoption of expressions and actions more suited to adults. I still find it disturbing, though.
I'm sure I'll earn the ire of many for daring to criticise a cultural icon like Indian classical dance, but it's an authentic opinion that I'm willing to stand up for. The doyens of the art should evolve a 'G' rated version of classical dance that is safe to teach to children, and progress to the unadulterated version when the students are older.
On the other hand, teaching classical dance could be seen as the new way to raise your child's EQ! (Stampede of Asian feet heard in background.) Sigh.