Zoe is the queen of the swamp she has married to the swordsman Zoro of the strawhats and they had 9 kids and their order of birth is :

1st : Zorky ( boy ) 4 kids

2nd : Zoron ( boy ) has no kids

3rd : Zavok ( boy ) 1 kid

4th : Zoron ( boy ) 3 kids

5th : Zeena ( girl ) 5 kids

6th : Zeila ( girl ) 4 kids

7th : Zorkai ( boy ) 2 kids

8th : Zoena ( girl ) 2 kids

9th : Zoryo ( boy ) 1 kid 

They all are married and have kids so Zoe is a grandma.