I would always introduce family and friends in age order. But I think that reversing it isn’t a big deal, provided you start with the youngest and go to the oldest. It would be odd if you had a third child “[name]Victor[/name]” and started to introducer your kids as [name]Ingrid[/name], [name]Greta[/name] and [name]Victor[/name] instead of [name]Victor[/name], [name]Ingrid[/name] and [name]Greta[/name]. (Does that make sense?)
I usually list them in age order, but only if it flows nicely.
I do with my set of nephews from one of my sisters. [name]Keenan[/name], [name]Avery[/name], [name]Owen[/name], and [name]Anton[/name]. Also with another set of kids from another sister. [name]Garret[/name], [name]Cade[/name] and Aylssa.
But with my sister who only has two, I change it around. [name]Isla[/name] and [name]Henry[/name]. I think if there is more than two it is easier to say them in order.