You believe that if she lied to scum in order to save her life that she would be denied eternity in heaven? God would know the truth when she spoke her lie and would never punish her for that.
He would know what was in her heart.
That is a very difficult situation to understand indeed. And I am so often lacking in the right words to explain what I really want to say. So I am calling on a few FR Christians (daniel1212, Alex Murphy,and HiTech RedNeck) I know can probably answer better that I. I'll give it a try, then I hope that they will step in and fill in the gaps.
You are right about the part that God would KNOW what is in her heart..... but the question would remain, what exactly is in her heart if she could proclaim a false testimony as to her faith. For example: if your child was wrongly accused of something horrible and about to be killed for it, wouldn't you know that you must testify to your child's innocence, proclaim it loud and clear even if it might mean your death as well? What I am trying to say is that there are some truths so important, that to deny proclaiming them would be worse than death. How could you live on knowing that as your innocent child was being put to death that you did not try to save him? So the answer is YES, I do believe that God expects us as "Christians" to be ready to testify as to our faith in Jesus Christ, no matter what the consequences. However, in return He promises that the Holy Spirit will give us the courage and strength to do so.
The scriptures say:
“I tell you, whoever publicly acknowledges me before others, the Son of Man will also acknowledge before the angels of God. But whoever disowns me before others will be disowned before the angels of God." Luke 12:8-9