Panel 1: Since Lynn can't be asked to look back at old strips and see that Elly has always thought that she looks at least fifteen years older than she actually does, we have her drinking coffee with Connie and spouting errant nonsense about how a little while ago, she'd have taken grey hair and wrinkles in stride.
Panel 2: The problem is that that particular morning, she looked in the mirror and saw a middle-aged woman staring back at her. Connie finally gives Elly what she wants by saying "I know!" instead of the "You're joking, right?" that mean people who think that she and her feelings are nonsense and she's a moron they can laugh at as if she hasn't got feelings tell her.
Panel 3: The problem, Connie says, is that middle age doesn't creep up on unfortunates like them.
Panel 4: She goes as bleary-eyed and horrified as Elly as she whines that it attacks overnight.
Summary: This, I think, is what Connie's primary function is to be from now on: giving her friend a heaping helping of confirmation bias. Her secondary function will be to envy Elly the blessings she's too stupid to notice. This makes her a better 'friend' (only garbage people call her a sycophant) than people who tell her that she looks young and fit. Remember, Elly might claim to want to be happy but she hates the idea of being happy because she looks down on happy people.