Niece's Role?

What you have is mind is great, even though the 13 year old can also be a flower girl. There'se no age requirement and she may love the idea of tossing petals 😀.
However: are you sure you want the 2-year-old to be a FG? Are you having a 'supervising companion' for her?

View Quoted Comment 13 y/o specifically has made comments about thinking she's too old to be a flower girl😂
My main reason for all of the nieces (including the 2 y/o) being in the wedding is because all of their parents are in the bridal party. I'm thinking the 2 and 3 y/o might be pulled down in a wagon or something

View Quoted Comment

Okay LOL. Pulling them down in a wagon or whatever is a cool idea!

Based on what you said, I would do what you suggested.

That way the 5 nieces are already involved but you can ask one or two of them to perform a reading, especially the 10 YO and 8 YO?

View Quoted Comment Oooh that's a good idea!

If you ask them to do a reading make sure you ask *them* and not their parents. When I was a kid I *hated* reading out loud even though I loved (still love) to read.

View Quoted Comment Yes, absolutely! Good point, thank you!

How about the 13, 10 & 8 year old are program/guest book attendants? And if need be, they escort the 2 yr old down the aisle?

They can pass out programs, be flower girls, be ring bearers, read a small selection, hand out favors after cocktail hour, etc. I had one of my youngest nieces hold the end of my veil for me down and up the aisle which worked out pretty well.