My 11 yr old slipped in the bath and bumped the back of her head, she stayed conscious. should i take her to er?

Some basics: If she remembers the fall, has no loss of memory before or after& has always been alert it is most likely a minor event with no need for an evaluation much less an ER visit. Some of these will have a significant headache arise at any point up to a week after. They can eat/sleep in their usual pattern. Loss of memory/consciousness signifies a significant hit & need for a visit.