It is quite common to read that Eleanor was unofficially in charge in France. Back in the day, France was far from being a centralized power. I am not saying it is as messy as the Holy Roman Empire later on, but Duke and Count had a lot power and ready to challenge the King's order.
Eleonor was the head of the most powerful duchy in France, and had an education toward ruling her own land. She married Louis the Young (or the Pious) who was a second son and not supposed to rule: he had a religious education instead. He was clumsy and naive, she was ambitious and ruthless: she sealed alliance, opposed the pope multiple times, put down rebellion merciless (hijacking noble's children, burning village and church...), and so on.
After the 2nd Crusade (that Eleonor took part), Louis the Pious, still weak-willed, started to get stubborn and started to not took advice from anyone. This kind of lead France to its doom (hopefully, the 3 following Kings were highy skilled and managed to save the Kingdom: without Philip August, France and England will be the same country). Nobody know for sure which one asked for marriage annulment: Eleanor probably knew she will not get anything from him anymore so my guess is there. But if it was Louis who asked, this was probably one of the dumbest idea in the known history.
But sure, she neither ruled over France nor England stricto sensu, she just had a huge influence over the two Kingdoms.