Is it obligatory to perform ghusl to cleanse from janabah after masturbating and after menstruation, and is wudu valid for prayer thereafter?

Masturbation is forbidden and harmful. It is obligatory to stop it and repent from it. Puberty is established by the appearance of coarse hair around the private parts, or the emission of semen, or completing fifteen Hijri years. For a female, it is also established by menstruation. As long as you menstruate, you are religiously accountable. Masturbation does not necessitate ghusl (ritual bath) unless semen is discharged. If janabah (state of impurity requiring ghusl) and menstruation coincide, one ghusl is sufficient.