You know what the great thing about sisters is? When your daughter throws up at 3:30 am because she's been eating a lot of strange party food, your sisters are there to help clean up. (Of course, Darwin wonders if they'd even been in bed, but that's beside the point.)
And when the baby throws up the next day for the same reason, you can count on your siblings to run and find the cleaner and towels and help wash the baby, who wails and pees in the shower.
But you can't count on your siblings to make sure the nieces don't eat junk. "The baby ate a pickle!" "She had some horseradish cheddar!" "I gave her some raspberry iced tea!" No, some things you have to do yourself.