This is the 12251st most frequent Turkish word.
haklarına
"To their rights" or "about their rights."
In this sentence, "haklarına" means "their rights" and refers to the rights of the children, using the possessive suffix indicative of third person plural.
Çocukların haklarına saygı duymalıyız.
We must respect children's rights.
Here, "haklarına" again means "their rights" and emphasizes the importance of defending the rights owned by individuals.
Haklarına sahip çıkmak herkesin görevi olmalıdır.
Defending their rights should be everyone's duty.
In this context, "haklarına" refers to the rights of animals and is used to highlight consideration towards them.