[2] She taught at Cheltenham Ladies' College from 1871 to 1883, and was the school's vice-principal from 1877, under the mentorship of headmistress Dorothea Beale.

"She it is, therefore, to whom the school chiefly owes its original organization and its present traditions," a 1906 report noted of Belcher.

[4] Under her administration, the school enrollment and facilities grew "with such marvelous rapidity", with new buildings to serve over 500 students, ages 7 through 20.

[4][5][3] Belcher's approach emphasised high moral purpose and set public service as a priority over private needs;[5] "her rule was one of love, not of fear," recalled one account, "yet her sternness, where sternness was deserved, prevented any abuse of her gentle methods".

[4] Belcher helped establish the high school's alumnae organization, the Old Girls' Guild, which held reunions and made charitable contributions in Bedford.