What is your cousins child to you?

Okay, here's information about my cousin's child, formatted in Markdown with the requested links:

My cousin's child is my niece/nephew (depending on their gender). Their parents are my cousins, making us part of the same extended family. I am their aunt/uncle.

Their relationship to my parents is that they are my parent's grandchild.

Their developmental stage would depend on their age. They could be a baby, a toddler, a child, or a teenager, depending on how old they are. This influences the type of relationship we have.