Agreement of possessive and nouns or pronouns

Both of the students forgot (his/their) notebooks.

(a)  

Neither of my sisters owns (her/their) own house.

(a)  

Matthew likes (his/their) meat cooked well done.

(a)  

The Wexlers send (his/their) children to private school.

(a)  

One of the women has retired from (her/their) job.

(a)  

This isn't Connie's jacket. It's (my/mine)

(a)  

Diana's children are in custody. She insisted them to stay with her because the children ar (theirs/hers/her).

(a)  

Of course John's children look like him. they are (theirs/his/him)

(a)  

The little boy is holding (his/her) mother's hand.

(a)  

All of the girls had (her/their) own bedroom in the apartment

(a)