This did not happen in the novel. The studio producing the manhwa deleted many scenes that happened in the novel and completely changed some of them.
In reality, this manhwa is considered very bad compared to the novel.
You will find what you want in the novel, as the studio working on the manhwa deleted many scenes that show the development of their relationship.
I also advise you to read the novel starting from the first chapter.
You will find it on this site...
Yes they will have two more daughters and Rose is already pregnant with one of them but they won't find out about it for another two or three months and the next baby on the way will be named Aurora