Renee, Barbara, and Quinn are cousins. Renee is nine years old. She has an average weight and height for her age. She is beginning to develop breasts. Barbara is eleven years old. She also has an average weight and height for her age and is beginning to develop breasts. Quinn is twelve. She is short and slim. She has not yet begun puberty.
Which conclusion is most reasonable, given the above information?

Renee is precocious.
Quinn is entering puberty late because she’s thin.
The cousins are all within the normal range.
Barbara will menstruate first.