i think they have one child and will shower it with so much love. they're definitely big on making memories, because jung was expected to be very responsible for his age and was constantly observed and never felt comfortable at home and seol had to watch her parents struggle and she felt the weight of everyone's burdens, so all they want is for their kid to be happy and carefree, which is how they raise them. i can see them taking the kid to orchards, planning holiday parties at home with just the three of them, watching and filming all of their kid's performances, snuggling all together in weekend mornings, etc. with the money for a comfortable lifestyle (their dad is literally a ceo) and two adoring parents, i know their child will grow up feeling so loved.

other headcanons:
- jung is a great teacher. the way he taught areum letters and how he tutored seol shows this quality and i think he just explains things so well
- at first, seol was flustered by parenting and felt so clueless at times, but jung was so good with the kid in its toddler years which made her feel a bit jealous lmao. but as the kid grew up, she was great at giving them advice, especially in their preteen/teen years, while jung was the one feeling a little baffled with teenage moodiness (since he wasn't allowed to express emotion and his dad only ever responded by shutting him down, which he felt inclined to do too but quickly recognized it and stopped himself).
- they have a vacation home somewhere in europe (jung basically admitted to touring europe) and they go there every summer. then they go visit his parents and then spend the rest of their summer break with her family
- this is inspired by joy's fanart but they made the baek siblings the unofficial babysitters lmao
- they raise their child to always speak their mind and never repress anything 
- they all definitely game together as a family. don't ask me why, it's just true
- since jung is busy as a ceo, he finds it hard to make it to certain events and feels bad about this as seol naturally has to be the more active parent. he makes it up by taking the child to dinner once a month to catch him up on everything and he just lets the kid talk and eat whatever they want without any lectures
- i just know seol has a hobby exclusively for her and her kid, like gardening, crocheting, or trying a bunch of local restaurants, that they bond over
- the kid definitely inherited jung's love for collecting things
- they don't hesitate to splurge on the kid and are the types of parents to rarely buy any nice stuff for themselves but they will buy anything for their child