Who was the woman Zeus had 4 kids with?

Answer 1

I believe you're talking about Leda, who bore four children at one time, but only two of those children were his. Leda laid two eggs (because Zeus slept with her in the form of a swan) - in one egg, there were two girls, Helen and Clytemnestra. In the other egg, there were two boys, Castor and Pollux. However, only Helen and Pollux were the children of Zeus. Clytemnestra and Castor were the children of Leda's mortal husband Tyndareus.