Books where main character protects a child

[Ellise]

I’m looking for books with a plot similar to movies like Safe or Man On Fire. Similar Books are The Littlest Witness by Jane M. Choate and Three by Jay Posey. In other words one where the main character protects a child/young person from harm. Doesn’t have to be action but preferable. Also the more emotional the better. Bonus points if they start off disliking each other