A woman wants to make shahada today but she is in menses, as for shahada i think there is no problem to make it while she is in menses but what about the ghusl after shahadah?
She should not postpone her shahada and accepting Islam. She can say it and make ghusl. Or she can pronounce her shahada and wait to make ghusl till she is purified from her menses. Saying the Shahada and believing in the heart makes her a Muslim.