The School Queens by L.T. Meade

Meanwhile the young people enjoyed themselves vastly. Maggie was very modest with regard to her tennis, but she quickly proved that she could play better than any one else at the Manor that day. The visitors walking about the grounds paused to remark on her excellent play and to inquire who she was. She took her little triumph very modestly, saying that she was rather surprised at herself, and supposed that it was the fresh and delicious air of the country which had put her into such good form.

"She is ridiculously overmodest," said Isabel Tristram to Merry, "for she always did play every sort of game better than the rest of us. She is not quite so good at her books; except, indeed, at certain things, such as recitation. I wish you could see and hear her then. She is almost a genius. She looks like one inspired."