dear, as I can understand, here your major concern is your daughter maturbating at a very tender and young age. this behaviour In her could be a result of her underlying emotional instability that warrants an immediate attention and treatment. There are few mental problems in which such kind of behaviour is common. there are like anxiety disorder, depression. or emotional problems. as she is in her developing age , she is vulnerable to various stresses in life arising out of failure to Cope with surroundings or insecurities out of familial problems. how to go about it? - establish a trustworthy relationship with her--- very important Don t be critical. Try to understand if she is having problems in school or if she is upset or fearful of anything. This will give us some insight into her problem and guide us for a definitive diagnosis. After knowing the problems and issues in her life, you can consult a child psychiatrist. Releiveing her mental security is very crucial for her to develop a productive and stable life ahead. hope to have satisfied your concern. thanks you. stay healthy.