Four Children

1. first son Nivritidev was the incarnation of Shiva, 
2. second son Gyaneshwar was the incarnation of Vishnu and 
3. third son Sopandev was the incarnation of Brahma, 
4. fourth child Muktha Bai was the incarnation of Shakthi.

https://harekrishnainfo.blogspot.com/search/label/VitthalRukmini

karuna sindhu

 https://www.google.com/search?q=karuna+sindhu

First

 https://www.google.com/search?q=First+Avatar