Sometimes drying it out quick makes no difference, especially with a liquid spillage.
You could try really soaking it with some more m-power, brush it in well, then pull off a whole roll of kitchen towel, fold it into a big square pad and lay it on the stain. Then pile as many of her books on top of it as possible, to apply lots of pressure. Maybe put a plastic bag under the books to stop it soaking into the books cover
Bear in mind if there is still a large amount of the spillage in the backing and underneath it, you may be on a hiding to nothing unless you can get the carpet up and clean it from the back first.