Peace be upon you. The validity of performing ghusl for janabah during menstruation is a matter of concern. If a woman performs ghusl for janabah while she is menstruating, it is obligatory for her to repeat the ghusl after she becomes pure from her menstruation, as a precaution.
According to Ayatollah Khamenei: The validity of ghusl for janabah during menstruation is questionable, and it is safer to repeat the ghusl after menstruation.
According to Ayatollah Sistani: A menstruating woman can attain purity from other major impurities (not menstruation), so if she is in a state of janabah and performs ghusl, it is valid.
May you be successful in all good deeds.