Noor Salmaan's arrest for her alleged part in the Orlando shooting is appropriate. A court of law will determine whether she is guilty of a crime, and in the meanwhile it is necessary to place her under arrest. If she had a role in this horrendous crime she must be punished.
It is still a question as to whether or not Noor Salman knew about her husband's intentions. The fact that she was with him when he bought bullets at Walmart, does not mean she knew his intentions. The fact that she apparently "scouted" out the nightclub is another matter altogether. Also, the fact that they were texting during the incident is questionable as well. It depends on the context of the texts.
If it is true that she actually helped her husband in some way to carry out the crime, then she certainly needs to be held accountable for what happened. It seems that she wasn't the innocent, abused wife she made herself out to be in the beginning, and looks like she helped her husband in his terrorism. She deserves to be punished accordingly.
It appears that this woman knew more than she told investigators in regard to her husband's crime. Additionally, she disappeared while the investigation was still ongoing. Therefore, she should remain under arrest while investigators finish questioning her and finding out the extent of what she knew about her husband's plans and whether she should face additional charges as an accomplice.