LORD KRISHNA'S MOTHERS' - DEVAKI (KAIKAI) and YASHODA(KAUSALYA)

Lord Ram after his 14 years of exile returned to Ayodhya with his wife Sita and Brother Lakshman. The kingdom was pleased to have them back. His mothers were overjoyed to see them. Kaikai's eyes were filled with tears of happiness and guilt. She asked Ram to forgive her as she was responsible for sending Ram to forest. He was taken aback. He said to her that though he was not born to her, he had always loved her as his own mother and as a son it was his duty to obey his mother. He further added that he has and will always fullfil all her desires.
Kaikai was touched by his words and requested him to grant a boon. She said "In this birth I didnt have luck to give birth to you, but in my next birth you should be born to me as my own son". Ram smiled and nodded. Now it was Kausalya's turn. She said" Though you were born to me but i didnt have an opportunity to enjoy all your childhood mischiefs and innocence so in my next birth i want to raise you up all by myself, devoting everything to you as a mother". Even her wish was accepted.

In Lord Vishnu's eight avatar as Krishna
Devaki(who was Kaikai in her previous birth) gave birth to Krishna and Yashoda(Kausalya in previous birth) raised him up.
Ram, avatar of Lord Vishnu, was born to King Dashrat and Kausalya. King had 3 wives - Kausalya, Kaikai and Sumitra.