Having a flower girl and ring boy especially if you have younger siblings is not a bad idea, in fact, an adorable one. However, there may be a few things you might want to consider going through with the children before the big day.
First, have the children get excited about this day. Talk to them about the day and how important it is to you. The more you get at least one of the children excited the better. If you at least get one child excited about the wedding day, that one child can probably get the other one excited as well.

Go through the process with them. Show the flower girl how to throw the flowers high in the air and teach the flower boy how to walk steadily with the ring pillow. Have them practice it over and over again, and reward them when they get it right.

Have them practice in front of a crowd. Even if they have mastered the steps in front of you, they may become nervous when they see all those people and hear the music in the reception.
You may even allow the children to pick out their own attire. This will help ensure that the day of the wedding they like their attire and don’t want to take it off.
Don’t dress the child more than one hour before leaving to the reception. Children are messy and cleanliness is the least of their worries.
If the child is accustomed to naps and your reception is during their nap time, give them an earlier one! The last thing you want is a grouchy child.
Nobody of course is perfect, so don’t expect the child to be either. The worst thing that can happen is the children refusing to walk down that alter. In that case you can have either their mother or father escort them down for reassurance and comfort.

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