Finding a hole in the timeline now that I've got a chance for a second viewing so lets work thru this again.
Merry Creamer,(notice how close that sounds to Kramer) is adopted by Starman's parents and becomes Gimmick Girl or Merry, Girl of 1000 Gimmicks. In the show they haven't specified yet if it was an adoption or birth sister.
She marries Brainwave (villain) and they have a son Jr who's already in the show.
Brainwave is now Starman's brother in law. Jr now becomes his nephew.
They lure the JLA into a trap killing them and Starman.
This causes allegedly Courtney's dad not to show up for Christmas the same night. (It may turn out he was working the crime scene as a henchmen for the IJLA that night if he's really Sam Kurtis)
Merry freaks out about her brothers death, icicle kills her and makes it look like drowning. Brainwave mentions how cold she felt so that leaves the door open for a recovery with no major brain damage which has actually happened in real life with coldwater drowning victoms recovering after extended periods underwater.
Jr grows up without a mom. Courtney grows up without a dad. Courtney grows up best friends with Mary Kramer
The fly in the ointment here is Mr's Kramer who is unnamed and Mary Kramer were already in a relationship with Courtney and her mom. That makes the timeline not work unless Merry was already living under an assumed secret identity with her daughter prior to all this and the death by drowning and recovery is what promted Courtney, her mom, Mary and her mom to all 4 leave town to resettle elsewhere. It's a bit of a stretch to think she could have hidden a pregnency and a daughter for several years from a telepath like Brainwave also. She'd need a good gimmick for that, maybe something she borrowed from Doctor Fate.
A much smaller fly in the ointment, Sam Kurtis. It's hard to picture mom not immediately going "that's not the guy I slept with and made a baby with if he doesn't look identical. That leaves open the door where maybe Sam Kurtis will end up being Starmans secret relative of some sort that became the black sheep of the family or seperated twin at birth type thing since the Pembertons in general were wealthy enough to afford Pat as a full time driver mechanic for Sylvester and could afford full blown soap opera like twists and controversys. 4 more days until that loose end hopefully gets cleared up.
We still don't have a direct line confirmed yet for Mary Kramer being the daughter or relative of some sorts of Merry Creamer but it's not an uncrossable chasm and at the very least leans toward Mary Kramer eventuially becoming a new version of Gimmix.
Jacqueline Pemberton was the daughter of the Golden Age heroine Merry, Girl of 1000 Gimmicks. She created a costumed identity as Gimmick Girl and intended to follow in her mother's footsteps - only to tragically become the victim of a demonic assault on her first mission.
That comic version at least confirms in that reality Merry had a daughter and Jr had a sister. I don't believe Jr is dead now either. I know his mental powers saved him from the collapse.