What makes you qualified as to judge her abilities being a mother? Impressions you got from media? Then as far as I'm concerned all I hear about foster care: children are being clubbed to death, sleep in cages, malnourished, never see a daylight etc. Rightfully that's what makes some governments in other countries consider banning adoptions by US citizens or a least substantially toughen the requirements.
Oh it's not true, just media frenzy, few spoiled apples. Then give benefit of the doubt to a person's parenting abilities as well. There was nothing during past 5 months since her daughter was born to suggest Anna was not caring, loving mother. Did you observe anything? Heartbroken too. Yes there were mistakes, questionable behavior earlier in her life but who had not make some. Those don't mean person can't possibly change especially after such a profound experience as birth and/or especially death of the child. Quite contrary.
Honestly I've never expected to find myself defending Anna Nicole Smith but it just makes me sick that somebody so heartlessly suggests that somehow child would be better off without a mother in hands of foster care, unless there was absolutely 100% compelling reason for that such as history of abuse, carelessness toward a child etc.
If you'd give it a tiny bit of the thought you'd understand that from now on the life of that little girl is not going to be about her well being but about wrangling as much money out of it as possible. I'm pretty sure she would have been far better off with her mother protecting her.
I personally know number of examples of people with questionable past who become amazingly caring and protective parents often far more so than those from so called "proper" families.