The Prophet Muhammad, peace and blessings of Allah upon him, had seven children, three boys and four girls.
As for the boys:
As for the girls, all of whom were born to Khadijah:
1. Zaynab. For its meaning: what is the meaning of Zaynab?
2. Ruqayya. For its details see: Ruqayya
3. Umm Kulthum. For its details see this answer: What do Zarafshan and Kulsoom mean?
4. Fatima. For its details see: Advice on Imran Layachi for baby boy and Inaya or Soumaya Fatima for baby girl