Would newborns necessarily need their moms after the birth tho? Of course it would be preferable and I get what you mean but there would definitely be other people available for the baby (father, wet nurse, and maids), and as we can see he’s survived even though she left. But im sure she viewed it as a transaction not really the warm motherly way of wanting to give birth to a child. She thought HAD to in order to go home, so I can’t really fault her.
I get that too but once again, during these times didn’t nobles also use alternatives like animal milk and wet nurses? I thought during these times biological parents (nobles) did not directly raise their kids which is why we see so many stories of children constantly raised by their maids/nannies/governesses?
Perhaps, but she's forcing them to use this alternative (they're not choosing it on their own) and she's a modern person with modern values. Moreover, she already loves her husband enough to get jealous over the idea of him finding someone else to replace her, so no, it's NOT merely a transcation for her, anymore. I don't blame her, but I'm sad she had to betray her own heart.
She also already dreams of seeing her baby grow up... ugh. Moreover, every grandma I know would fall so rabidly inlove with their grandchild, they'd immediately compel their adult son/daughter to make that baby a priority. That's why I believe she's not being fair to her mother (her mom wouldn't ask her to abandon her baby, if she thought her own daughter was "happy"... I think the FL is actually feeling guilt for being happy while her mother is dying without even knowing what became of her missing 19 year old daughter. But that's not the same as her mother outright blaming her)

Eh, it's messed up that she has to choose, but when she does, a newborn should always be the priority, IMO. Once they're born, priority, period. Cause without their mom they're way too asbolutely defenseless, whereas old people still have at least some of their leftover skills from their life already lived up to that point. No one should be sacrificed, but newborns NEED their mom.