Hi Nada,

Leur can be both them or their, depending on whether it is an indirect object pronoun as in the lesson you pinned or a possessive adjective. Take a look at the following Kwiziq lesson for this other use of leur -

https://french.kwiziq.com/revision/grammar/use-notre-nos-votre-vos-leur-leurs-to-say-our-your-and-their-possessive-adjectives

I hope this helps!

No, I WILL EAT YOUR KIDS, ( really?),

 'leur' and 'les' are different object pronouns and depend on the verb you use here. Please take a look at the relevant Kwiziq lessons -

https://french.kwiziq.com/revision/grammar/when-to-use-le-la-l-or-les-to-replace-nouns-direct-object-pronouns

https://french.kwiziq.com/revision/grammar/when-to-use-lui-and-leur-to-replace-specific-people-with-him-her-and-them-indirect-object-pronouns

Bonne Continuation!