They're a wealthy couple so won't have to worry about putting a lot of responsibility on their children when they grow old (or even having to spend all of their time looking after this one and getting exhausted!) so good for them if they want another baby.
Personally - no. I wouldn't have wanted a child so late in life, but we are all different, and if people want a child, can have a child, and are able to look after a child, then I wish them well.
I've got a delightful little grandson that I look after one day a week, and while he's gorgeous and a very easy child (MUCH easier than his dad was! 😄), I'm like a wrung out dish rag by the end of the day.
A child in my son's class many years ago had a mam who was one of (IIRC) 8 children who were born over a long period. The mam told me that her mother used to joke about collecting her pension and her child allowance on the same day 😅. (Probably a little exaggeration, but amusing)
EDIT: Just had a look - she had a little girl, and both of their daughters have been given what I would call "normal", if slightly old-fashioned, names - June Violet and Barbara. (My DS would have been "Barbara" had he been a girl). Just nice to see a bit of "ordinariness" in the Savage World of the Sleb. 