I don't think she thought about his death. I think she thought about ending her own angst. His death was a means to an end for her IMO. I don't think she cares one way or another.
Her journal entry after the murder, after returning to Yreka says it all:
"Utah was GREAT!!!!!!!!!!"
She cares. I think she absolutely relished seeing him powerless and in pain, dying as SHE killed him, screaming her hate of him all the while. I think she shot him last out of sheer hatred, even knowing he was already dead. And I think it entirely possible she would have mutilated him still further if she hadn't run out of time. Seven years later and her hatred of him is still so intense that her need to express it trumps anything and everything else, including avoiding the DP.