Adulterous actress Kim Min Hee and director Hong Sang Soo are about to give birth... What will become of their illegitimate child's family register?

Director Hong Sang Soo and actress Kim Min Hee have had a child after a 10-year affair. The shocking news has drawn public attention to the fate of the soon-to-be-born child's family registry.
On the 17th (today), the Korean entertainment media "Dispatch" reported that Kim Min Hee is about to give birth. According to the media, Kim Min Hee and director Hong Sang Soo are
The couple is currently living together in Hanam, Gyeonggi Province, and is said to be more than six months pregnant and due to give birth this spring. Director Hong Sang Soo accompanied Kim Min Hee to the obstetrics and gynecology clinic.
He even accompanies Kim Min Hee to all of her medical examinations, and takes good care of her without worrying about the people around them. The two also seem to enjoy going on dates in their spare time.
Director Hong Sang Soo is still married. In 1985, he married Ms. A, whom he met while studying in the United States, and they have one daughter together.
In 2015, he met Kim Min Hee through the movie "Right Day, Wrong Day" and developed a romantic relationship. In 2017, he officially admitted to his affair at a press conference for the Korean premiere of "Alone on the Beach at Night."
The director filed for divorce from his wife A in 2019 but lost the case. Since then, he has maintained a legal marriage with A and is currently living with Kim Min Hee.
A said he had not heard about the news of the two children. According to one media outlet, A said in a phone interview with reporters, "(
"I had no idea about the pregnancy. I'm grateful that I was informed," she said. In this way, if a child is born between Director Hong Sang Soo and Kim Min Hee, who are not legally related, the family register will not be updated.
What will happen with the settlement? If the director's family register records her as an illegitimate child, Kim Min Hee's child's mother will be Mr. A, and she may be added to Kim Min Hee's family register as an exclusive.
Attention is focused on which family registry Director Hong Sang Soo and Kim Min Hee's children will be registered under.