We love your kids—we really do! However, if your invitation does not say "household" or "and family" please leave the kids behind so you can enjoy a night to yourself.
If your invitation says “and Guest,” then yes, if not, we would prefer if it was just you.
Sunday's Best is appropriate attire, but we want you to feel comfortable, so if those shoes are too high or that top button is too tight, let it all hang loose.