It is not normal for a seven and a half year old girl to have leukorrhea on her underwear, considering precocious puberty and infantile vulvovaginitis. 1. precocious puberty: precocious puberty refers to the appearance of secondary sexual characteristics of girls before the age of eight, under normal circumstances, the girl in puberty before there is no leukorrhea, after puberty, the ovaries began to secrete estrogen will have leukorrhea, seven and a half years old girl panties have leukorrhea, considered precocious puberty may be accompanied by breast development, pubic hair, armpit hair, and other symptoms. 2. infantile vulvovaginitis: seven and a half year old girl vulva development is still immature, can not cover the urethral opening and vaginal vestibule, if you do not pay attention to personal hygiene, long time do not change the wash underwear or fecal contamination, etc. will cause pathogenic bacteria invasion of the urethra, the infantile vulvovaginitis, pus secretion, usually accompanied by vulvar itching and other symptoms. The seven and a half year old girl underpants with leukorrhea is an abnormal phenomenon, it is recommended to consult a doctor in time, should be clear about the specific cause of the symptomatic treatment.