I don't see why Robert would hurry with kids if he had reason to think he'd still be up and running and perfectly capable of raising a kid at fifty, or seventy, or ninety. As said, the actual conception would be no problem even today - being an able-bodied parent would. But that's explicitly not a problem in the 24th century any more.
The issue would be whether 24th century medicine would guarantee safe maternity for Marie at an age above forty. But by the looks of it, Marie could have been several decades Robert's junior, removing the need for medical advances directly related to childbearing here as well. And Marie could have been an able-bodied parent without miracle medication even if Robert grew old and frail at sixty. So, not an unusual arrangement even in today's terms.
Timo Saloniemi
The issue would be whether 24th century medicine would guarantee safe maternity for Marie at an age above forty. But by the looks of it, Marie could have been several decades Robert's junior, removing the need for medical advances directly related to childbearing here as well. And Marie could have been an able-bodied parent without miracle medication even if Robert grew old and frail at sixty. So, not an unusual arrangement even in today's terms.
Timo Saloniemi