Lydia has definitely earned her right to sarcasm by saving most of my characters’ butts early on when they were weak.
I recall her wiping out the bandits of Valheim Towers nearly single-handedly while Rowan tried to figure out how to work a bow. It was particularly embarrassing when Lydia charged back out to the road just in time to save my little Imperial from the bandit chief. Then when Rowan sheepishly handed over pretty much all of the bandits’ pants for her to carry, Lydia’s eyeroll was the perfect response!