Why does my 5 year old niece mimick my 6 year olds every move?

She’s looking up to her, it’s cute. Now, if they were older or adults I’d seek an injunction or restraining order

because she’s a child. That’s what they do.

My 4 year old niece does the same thing to my daughter. They now also have the same haircut. I think it’s cute and if it bothered my daughter I would explain to her the age difference. If you tell her what an important role being the older cousin is, and explain how to be a good role model, you could turn a frustrating situation into a positive lesson.

When I was 10 my cousin did that to me, followed me around, did what I did, etc. I think she was trying to be like me but it was really annoying, then we both grew up and she went her way

It’s a high complement. I would help the older understand that she is being looked up to by her younger cousin. This is something that can be handled well with sweetness and humor.