Elsie J. Oxenham 
Secrets of the Abbey [EPUB ebook] 

“Joan! It’s too marvellous for words! Do you really mean you’d have me?” Jen, just arrived at school for the summer term, pushed back her yellow plaits and gazed up at the May Queen with wondering eyes. “It’s just terribly good of you, Joan!”
“I’m afraid it isn’t, ” Joan said, laughing. “To be quite honest, Jenny-Wren, I’m thinking about myself as well as you. I really want you, so it isn’t good of me at all.”
“Oh, but that makes it perfect! I’ll just love to be your maid! I thought you’d want somebody much older, now that Muriel’s the new Queen; she was in your form and she did everything with you. I’m such a kid; I’ll be no use to you.”
“Fourteen isn’t such a kid as all that, ” Joan said. “I shall expect a lot from you. I shall make use of you in all sorts of ways.”