Elizabeth seems to be a hold-over from a fifties screw-ball romantic comedy. She plays at having a career as a school teacher, she combines smug idiocy with a level of naivete that qualifies as a lethal mutation and has less gumption than 'Joey' from the U.S. version of 'Dennis the Menace'. Although she pretends to deny it now, soon she'll be pathetically grateful to be a stale photostat of Mom, married to a reasonable facsimile of Dad. In other words, Elizabeth is the Kate she wants. Candace began her existence as Good girl[tm] Elizabeth's high school nemesis. I mean, the girl just rebelled against all that Lynn thinks is true, good and beautiful and took it out on poor little Nizzie-poo. Later on, she became more sympathetic as we realized why she kept her mother at arm's length: the woman stood around wringing her hands while husband number two made crude sexual advance towards her daughter. (I think or HOPE she's really pointing at her jackoff ex-husband in that relationship). The result is a young woman secure in her self who, though in a steady relationship with a male friend, doesn't define herself as an appendage of some jerk with a schwanz. What gets up Lynn's nose is that Candace still doesn't respect or validate Elizabeth's lifestyle, she having moved from mockingly rejecting it to bemusedly pitying it. In other words, Candace is how she vents her frustration at Kate for not being a Stepford monster 'like she's supposed to.'
There's ANOTHER difference between the Foobs and their sidekicks: you could see yourself actually hanging out with Weed and Candace. She can't see that, so she sees them into goofy, over-grown rebellious kids who need to buckle down and grow up. All this anger because she defends a value system that made her life an ugly and unnecessary mess. Lynn, you are an ungrateful IDIOT!! You have nothing worth saying so STOP TALKING!!