It's not that odd that she hasn't been pregnant there are a lot of reasons people don't get pregnant; sometimes people just don't want children, some people don't think they have enough money/income to have children, the woman or her partner could have fertility issues, one could have non-fertility medical issues that make pregnancy difficult of dangerous, the woman or her partner could have inheritable diseases/conditions they don't want to pass on, people sometimes have mental issues which make them feel unfit to be a parent, some people adopt or want to adopt and are thus never pregnant.