I don't know.
Many shows have had similar seeming contradictions about various matters, and some have not been resolved for decades.
There is a somewhat similar problem in Star Trek: The Original Series.
In "What Are Little girls Made of?" 20 October 1966, there is a scene where Kirk talks with an android double who is going to impersonate Kirk and take command of the Enterprise.
KIRK: What about memory? Tell me about Sam.
KIRK2: George Samuel Kirk, your brother. Only you call him Sam.
KIRK: He saw me off on this mission.
KIRK2: Yes, with his wife and three sons.
KIRK: He said he was being transferred to Earth colony two research station.
KIRK2: No, Captain. He said he was continuing his research and that he wanted to be transferred to Earth colony two.
Kirk obviously had no reason to correct any mistakes Kirk2 might have made, but the way Kirk2 corrects a lie Kirk says indicates that Kirk2 does have totally correct information about Kirk's life, so Sam Kirk's family should have included a wife and three sons at the time that Kirk became captain of the Enterprise months or years before "What Are Little Girls Made of?".
In "Operation, Annihilate!", 13 April 1967, There is trouble on the colony planet Deneva, and the Enterprise receives a brief call for help.
MCCOY: Jim, did you know who that woman was?
KIRK: Yes. You were right a while back. My brother Sam lives on Deneva. He's a research biologist. That woman sounded like his wife Aurelan.
Sam is found dead, and his wife Aurelan dies, but their son Peter, aged about twelve, is alive and unconscious.
Later Kirk expresses frustration that they haven't found a way to solve the problem yet:
KIRK: I can't accept that, Bones. We've got fourteen science labs aboard this ship. The finest equipment and computers in the galaxy.
MCCOY: Captain, I understand your concern. Your affection for Spock, the fact that your nephew is the last survivor of your brother's family.
KIRK: No, no, Bones. There's more than two lives at stake here. I cannot let it spread beyond this colony, even if it means destroying a million people down there.
So Dr. McCoy directly state's that Peter Kirk is the last survivor of Sam Kirk's immediate family. And that seems to be a direct contradiction of the statement in "What Are Little Girls Made of?" that three sons of Peter Kirk were present to see Kirk off at the start of the five year mission, a few months or years before "What Are Little Girls Made of?".
Maybe Dr. McCoy made a statement without knowing for certain that it was correct, an all too common Human failing.
Maybe Dr. McCoy had looked up Sam Kirk in the Enterprise's computer database and learned that Sam's other children had died in an accident before the family moved to Deneva, making Peter the only surviving child.
Maybe the records showed that the other children had stayed on Earth or somewhere, perhaps with grandparents or other relatives, maybe to complete their educations, and never came to Deneva. Then McCoy might have meant that Peter was the only survivor out of those who came to Deneva.
Maybe the bodies of the other two boys were found and identified off screen and so McCoy knew that they were dead.
Maybe the other two boys went to Deneva but were not at home or in the city. Maybe McCoy didn't know where they were and assumed they were dead. Possibly those two sons of Sam actually had exciting adventures trying to escape that should be told.
Possibly the android double of Kirk was wrong and three sons of Sam Kirk did not go to see James T. Kirk off on his mission - maybe Peter was an only child and Sam didn't have any other sons or any daughters.
But those suggestions are just possible ways to explain the seeming contradiction.
Some alert fans might have noticed the contradiction as early as when "Operation Annihilate!" was first broadcast on 13 April 1967, which was 52 years, 4 months, and 6 days before today, August 19, 2019. Fans have certainly discussed it for decades.
And I think that various Star Trek novels and fan fiction stories have suggested some of the above solutions. But Star Trek novels aren't canon except in the universe of Star Trek novels, and fan fiction isn't canon except with itself.
The official canon of Star Trek includes only Star Trek movies and television episodes, and is vast and complicated and full of seeming contradictions which bug some fans a lot, causing them to spend a lot of effort thinking of possible explanations. The extended universe of Star Trek novels, short stories, comic books, comic strips, reference books, tech manuals, games, etc., etc., etc. is much vaster and even more contradictory, so adding it to the official canon of Star Trek is usually considered a bad idea.
And there has been no explanation of the actual number of children in Sam Kirk's family in the official canon of Star Trek in the 52 years since the contradiction happened.
I can only suggest that some of the solutions suggested for the problem of Sam Kirk's children might be analogous to some possible explanations for the seeming contradiction in the number of Lemond Bishop's children.
Oh, and if there is any way to contact the creators of The Good Wife and The Good Fight you might send them a letter or e-mail suggesting that they explain the contradiction before the end of the shows, instead of letting people wonder about it for over fifty years!
[added 06-06-2020, This post mentioned and is linked to in post # 11 here: https://www.trekbbs.com/threads/script-blunders.304609/1 ]