Too late to add to a wedding party?

I think this has a lot to do with your relationships with all the children and why you want to add them. Are you equally close to them all and/or their parents? Like a pp mentioned there is the potential that this both "insults" those asked "last minute" (probably more likely their parents than the young kids) as well as the older kids who you asked a long time ago ("I thought I was the FG????").... I'd think carefully about how it might be interpreted by everyone. Will the child with Asperger's find it even more stressful for there to be a group of children, who he might not know well?

FWIW Daughter had two FGs (8 & 4) and two RBs (10 & 6). They were all siblings, so if she wanted the 8 yr old (who she wanted very much to be the FG) she didn't have much choice but to ask them all. Honestly, four kids in the wedding (and dealing with their mother) was her single biggest stress of the entire wedding. The four yr old shrieked through the entire rehearsal dinner (like ear-piercing), not because anything was wrong, but it's one of her attention-seeking behaviors and her parents did nothing to stop her or remove her. For the processional, the 10 yr old walked with the 4 yr old, then just behind them were the 6 yr old and the 8 yr old right before the bride and FOB. Literally, 2 seconds before the 10 yr old was going to walk, he turned around and slugged his 6 yr old brother really hard in the stomach (right in front of B & FOB). They stood there for a second panicked that they were going to end up in a fist fight at the top of the steps down to the aisle just before the bride was to enter.... Luckily the 6 yr old shook it off, and the wedding started just fine, but it was the nightmare daughter had had multiple times, happening right in front of her. The kids all sat in the second row with their dad (mom was a BM) during the ceremony. In the video, in the middle of the vows, the 4 yr old can be heard whining about not being able to see and then there's a bunch of shuffling while her dad pulled her into his lap.... Videographers couldn't edit that out without editing out the B&G saying their vows.... In the big picture, for family harmony, daughter felt it was "the right thing" to have them all in the wedding, but in hindsight, she would have seriously considered not asking any of them. Unless your relationships will all these children are such that you truly WANT them in the wedding, I'd let it go. If you really want to you can always make up some kind of "honorary" jobs for them (like carrying a sign before the processional and then going to sit with their parents, etc.) and/or having them dress a certain way, but your life will be much easier in the long run.... Good luck!

My flower girl is going to be turning 21 two weeks after my wedding....there is not a specific age range for wedding party members...One word of caution is be careful adding too many young kids because you have to make sure you have someone available to wrangle the kids and keep them entertained. A friend of mine had 2 flower girls and 2 ring bearers and their part of the processional took nearly 20 minutes because they were not happy about walking down the aisle. They just wanted to play. When someone finally went and picked them up and carried them down to the front they were screaming and crying and running around, distracting everyone else (including the bride and groom) from enjoying the ceremony.