that she was trying to shield her husband makes sense to me... it is a natural reaction... now my husband would have been mad at me if i had tried to shield him... my instructions are to move the hell out of the way... if he dies trying to defend us, then he dies... but he sure as heck does not want me to be harmed in the process... (same instructions to our kids)...
If she was shielding him, it means that she knew he was about to get shot, but HE did not know it. I think the shooting happened SO fast there was no way either of them knew. (Again, pure speculation.)