The death seems like an unintentional consequence of their drunken fight to me from the limited information presented here. So, while I agree that some form of punishment is necessary, is "throwing the book at her" in order to fulfill some real or imagined gender disparity really the answer?
If the boyfriend killed the girlfriend instead, would we even be asking the question? I doubt it.
Is making a point by sending this woman to prison for so long that her kids effectively lose both parents the best option?
Again, if the father killed the mother instead, would he be considered the best option to raise them? Seems like they're gonna live elsewhere regardless of the outcome here.
Of course, that depends on things which we don't have access to yet, like whether she's regretful of her actions and willing to take steps (like getting in a treatment program) to deal with her drinking and anger issues.
Suspect that most guys that kill their wife/gf regret it at some point or other, but taking an anger management class doesn't make it better.
Only reason they haven't already locked her up for a nice long time is because the gender roles are reversed. A guy in the same situation wouldn't stand a chance...