It is her play time to watch his movie有错吗

你怎么前面是her后面是his?
还有
it's time (for sb) to do sth 是固定格式,不能拆开,想表达这个意思可以写成：It's time for him to play and he watched movie during this time.
或者写成It's playing time,he watched movie to kill time.
play应该改成playing,形容词,修饰time