I guess thats what happens then because i think do everything that you said i should, and she still dies so until i get ME2 she is going to die every time 
This is just an idea you can try. I don't have Genesis for any of the games, so I don't know how it can affect the savegame. But with Gibbed ME3 save editor in the
Raw tab -> Plot -> Known Variables -> Is ME2 Import True/False
You could check and see if this variable is set to True. I don't know if the Genesis does this for the savegame. It might be that you have a mix of different variables that are coming from ME2 saying that Miranda should live / not live, and then ME3 will go ahead with default choice due to the variable conflicts.
No idea if it will make any difference, but it could be worth testing.