This is Kate's and Lucy' room这句话对吗

This is Kate's and Lucy' room这句话对吗
This is Kate's and Lucy' room这句话对吗

This is Kate's and Lucy' room这句话对吗
首先你那句表达不正确,
正确的为：
This is Kate and Lucy' room.

我觉得应该是This is Kate's and Lucy's room