Sayyiduna Abu Malik al-Ash'ari (may Allah be pleased with him) says that next to the Prophet (peace and blessings be upon him) in prayer were first the men, then the boys, then the women.
This chain is weak, and the first one is stronger; and Allah knows best.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5166