The Well-Wishers (Tales of Magic #6)

Just when the children thought the magic in the old well was all played out (that is, if it was magic!) and had sworn an oath in blood not to make any more wishes until the well gave them a sign, Gordy—in a reckless moment—told it to get going with its magic, or else! Something certainly did begin to happen then, whether it was magic or not, for a strange, witchlike old woman came to the children's secret house in the wood soon after and led Gordy away.

The most unexpected things kept on happening all through that eventful autumn, just the sort of things an unpredictable wishing well might involve them in, from reforming a nearly delinquent juvenile at school, keeping apple trees and romance in bloom, and rescuing a damsel in distress, to helping a new family settle in the community.