Loud and noisy or sweet and funny, all depends on your point of view, and the decision is up to the couple whether to invite children or not.
Many couples for their weddings prefer the choice not to include the presence of children in the program.
No guilt, etiquette says no children in the ceremonies.
Guests have to accept the decision of the future husband and wife, remember that if the participation is written only your name means that you are invited and not your children, but if you find written "and family" or "and children" then you can take them with you.
At this point, how to dress them.
For him pinstripe trousers and white shirt or polo shirt and white pants
For her sleeveless dress Fendi
Under 12 months:
Boy romper salopette
Girl white sleeveless dress with embroidery Miss Blumarine