Even is she realized the baby was bleeding out, she may not have known how to stop it.
There are just so many unknowns in the story but IMO, murder involves intent and I don’t know that deliberate intent could be proved in this case unless there were really extenuating circumstances.
There are other charges available like manslaughter. A big problem for awhile has been to overcharge by prosecutors. OJ could have been in jail for decades now if they hadn’t gone for a death penalty or life without parole charge. Many jurors just can’t pull the trigger unless they see it on film or have a confession. But 30-40 years for a lesser charge knowing that evidence may come in later that could cut it short is easier on their minds that they aren’t responsible for putting them to death.