Sayyidah Aishah (may Allah be pleased with her) said that the Messenger of Allah (peace and blessings be upon him) said: "The prayer of a woman who menstruates (an adult woman) is not accepted without a head-covering."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحجر / 11311
Muhammad said that Sayyidah Aishah (may Allah be pleased with her) went to Safiyyah Umm Talhah and saw her daughters, and said: A girl was sitting in my room when the Messenger of Allah (peace and blessings be upon him) entered the room. He threw his wrap towards me and said: "Divide it into two parts; give one part to this girl and give one part to the one who is with Umm Salamah. I am certain she has reached puberty," or he said: "I think both of them have reached puberty."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحجر / 11312
Sayyidah Umm Salamah (may Allah be pleased with her) said: When a girl menstruates, it becomes obligatory upon her to cover herself just as it is upon her mother.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحجر / 11313