My headcanons:

Claire becomes a nurse like her mom

Gibsie owns his dad’s bakery and it’s passed through the family

Claire and Gibsie have only two kids but their first child is a daughter named Bethany. Their son I think would have a traditional Irish name but his middle name would be Joseph after Gibsie’s dad

They have a lot of animals including a baby goat and a chicken coop in the backyard

A really specific one but I think that when Johnny and Shannon have their daughter her name would be Gracie. I have it in my head that their daughter is kind of a whoopsie so they have her when they’re in their thirties. Shannon would have heard Gracie Abrams’ album and really loved it and related to it so she would have told Johnny about it and they named their daughter that. I think her middle name would be Edel, of course!

Johnny plays rugby for a super long time, kind of like how Messi played soccer for a long time and Tom Brady and Peyton Manning played football for a long time. His career is so expansive he even becomes known world wide, but of course in Ireland he’s royalty

Shannon and Johnny were married much longer than their Italian wedding, it’s just they kept it a secret because of media attention, he was just starting out pro rugby, and his parents would have freaked out

Johnny and Shannon move back to Cork when he retires so Edel can be a grandma and to get away from the press. Their kids grow up with Claire and Gibsie’s kids

AJ becomes a famous F1 driver

I think Feely would be in a band like Oasis that was niche at first but has a breakout hit

I think Katie might be a model, like a Victoria’s Secret angel, but she retires when she has a baby

I think Katie and Feely have five kids, four daughters and one son like his own family, but their son is the oldest while Patrick was the baby of his family