I have not followed the case that closely, however, I have to assume that the court ordered a psychological evaluation for her early on. Seeing as how she is not committed, she must have passed. Which means she did knowingly and maliciously murder her husband. No, she should not have custody of her kids. I pray that DHR is keeping a close eye on her and them.
Finding out you're in a bad realationship, means get a divorce. Not kill your spouse.
Again, I have made some assumptions here, and might be wrong. But this is my opinion based on my knowledge of the situation.