Shawn 211,

Simply because a murder charge is not under consideration.  There is also recent and local precedent both she and the court must be aware of, namely that pleading to, or being found guilty of a single count of negligent homicide does not necessarily equate with much prison time.  Given that reality, it would be a foolish decision in the extreme for her to abandon her home, her friends and her family, to adopt life as a fugitive.  And, unlike an accused embezzler who may have conceivably secreted a large stash of liquid assets, a judge would probably consider her a minor flight risk given her economic reality and lack of serious criminal history. 

There are thus several good reasons for her to stay and see her day in court and few if any reasons to flee.