I don't like speculating on strangers' fertility or lack thereof, but she seems in the perfect space in life for a kid, so I did wonder why she made a big deal of being a dog mom and never had a child. She's getting up there in years (sorry just a medical fact) and when people are comfortable financially and have enjoyed their hubby for a bit they start longing for a family.
Again, this is all out of character for me, just some thoughts I had. Her choice to have a baby or not is hers and her husband's alone.
On a related note, I wouldn't like raising a kid in Monaco. It seems wonderful for avoiding tax, gambling, events, and parties, but I wonder long term how a kid growing up there would feel. I saw here or another thread that some people live outside of MC where they can have larger more relaxed properties close by in France. Maybe this is what she does? Maintains two houses.