How can I involve my niece in my reception?

Hey y'all!!

Husband and I got married elopement style October 30. Weather ruined our waterfall ceremony but we found something indoors that was beautiful.

It was great.

Anywho, we are having a reception in January to share the video and photo with family and celebrate. My four year old (she'll be five in February... terrifying) niece wants to be a pretty princess and be apart of the day..

What ideas do y'all have to involve her with the reception?