Arguably she could have decided to have children because with her age and the possibility of a 5-20 year sentence that having children may have been impossible had she waited.
I think it's unfair to draw attention to this particular decision that she has made as as callous or scheming when in reality there are already plenty of examples and her having children may have been the most human of them all.
I read, like 10-15 posts daily on social media where people mentions that they have decided to postpone parenthood simply because their circumstances aren't favorable (mostly finance related).
When I read about Holmes in light of those posts, I'd say she is some sort of callous and insensitive person. She never once gave a shit about ethics, people's lives etc. Who knows she decided to have kids simply because it might reduce her sentence rather than because she really wanted to have kids like rest of us do.
There are special female sections at some jails esp for woman that is pregnant or has babies - afaik they can stay with the mom until they need to go to school.
I think it's unfair to draw attention to this particular decision that she has made as as callous or scheming when in reality there are already plenty of examples and her having children may have been the most human of them all.