Of course not! U can have as many or as few as u like. There's really no set rule. Just bear in mind that a childs attention span is considerably less than an adults and when one child gets irritable, the others are likely to catch the bug!
That said, 3 is ok, tho maybe u could have a rethink if FH feels strongly about it. All the best!
I don't think 3 is too many.
I think it looks beautiful when I see more that one flower girl, I saw a wedding where 1 flower girl (the youngest) walked in front of the bride and tossed roses, and the other 3 flower girls were behind the bride holding her train just slightly off the floor.
GOOD LUCK!!
I've seen weddings where they have one maid of honor and a half a dozen flower girls who help with the dress and the flowers and vail... It makes some awefully cute pictures in my wedding we have two flower girls and two ring barers 3 ushers and three grooms men we dind't want to leave anyone so we gave the boys and girls in out family specific roles.
The only one who couldn't be in my wedding was my littlest sister who is 12, her father said no. Sucky
I am having two and it would be more but thats all of the little girls in my family that I have. We are having my fiancee's twin neices. They are going to wear wings and halos like little angels. Just like I have heard from my friends, its your wedding and so do want you want. If it is really unique that just means more people will remember it :)
I actually had three little girls in mine, two of the girls gave people in the audience long stem roses (make sure you shave the thorns off) instead of throwing petals on the ground and the other girl walked in the middle holding the pillow with my husbands ring. It was the cutest thing you have ever seen and made for wonderful pictures! Best of Luck