First off, fuck religion in general. It's all a load of bs used by people in power to control others.
Second, Aisha is considered by Muhammad and Islam scholars to be pretty much his equal. Reducing her to that of a child forced to marry an adult takes away the reality of the situation.
Third, she may not even have been nine. She could have been a preteen or even a teenager. This would not be uncommon for even non-Muslims in history.
And last, who gives a shit? There are enough issues with Islam that to attack them over what her age is is missing the forest for the trees. Not to mention this is the millionth time we've talked about this.