I have found some copies of several of May Baldwin's other books at Abebooks.com.
They are A RIPPING GIRL, DE VICTORIA SCHOOL, NELL, MYSIE, THE GIRLS' ETON, HOLLY HOUSE AND RIDGE'S ROW, HILDA'S EXPERIENCES, THE GIRLS OF ST. GABRIEL'S, THE FOLLYS OF FIFI, POPULAR GIRL, A SCHOOLGIRL'S DIARY, TEDDY AND LILLY'S ADVENTURES, MRS. MANNING'S WARDS, SPOILT CYNTHIA AT SCHOOL, PEG'S ADVENTURES IN PARIS, BARBARA BELLAMY: A PUBLIC SCHOOL GIRL, JEAN AND THE BOYS, KENYA KIDDIES, THAT LITTLE LAMB, DORA A HIGH SCHOOL GIRL, SARAH'S SCHOOL FRIEND, IRENE TO THE RESCUE, SYBIL OR OLD SCHOOL FRIENDS, GOLDEN SQUARE HIGH SCHOOL, MOLL MEREYDITH MADCAP, A PLUCKY GIRL, THAT AWFUL LITTLE BROTHER, A CITY SCHOOLGIRL AND HER FRIENDS, THE SUNSET ROCK, MISS PETER, TROUBLESOME TOPSY AND HER FRIENDS and A YEAR IN NATURELAND. There are copies in German of several of the books. She was quite a prolific writer, wasn't she? I may have to try get some of these. If there is anyone out there who has ever read any of these or heard of May Baldwin, please let me know.