Wedding entourage walking down the aisle

My fiancé’s sister just asked us if we plan on including her 16 year old son, his nephew, as part of our wedding party and walk down the aisle/ be a part of the wedding somehow. While I think it’s a sweet idea, it’s not something either my fiancé or I thought about. While I don’t think it was right of her to clearly imply that she thinks he should have a place in the wedding, it’s never our intention to offend anyone.

I suggested to my fiancé that maybe his nephew could read a poem or something.. but my fiancé says he wouldn’t want to do any public speaking. So I’m thinking maybe it could be just as simple as letting him walk down the aisle alone? Would that be weird? Is there like a guideline to who walks down the aisle or can I basically be like my wedding my way? Lol

Also do siblings that arent in the bridal party walk down the aisle as well? My brother isn’t a groomsman and none of his sisters are my bridesmaid.