I'm not an atheist but there is this thing we have called freedom of religion here on the West. It is unfortunate that she was 'attacked'. Ideally, we should be able to converse in a respectful manner.
Tell her to ignore those people who 'attacked' her. Ultimately athiests can not prove their own belief. These athiests who attacked her do not have an open mind to other possibilities other then what they can imagine in their own closed minds.
Otherwise they wouldn't have attacked her. They can express their opinion but attacking someone for their belief shows their own insecurity. The freedom of religion is born out of a need, not to deny that there is an absolute truth, but to give each person a basic human dignity and therefore human rights irrespective of their religion or beliefs.
Everyone has a right to their own opinions and beliefs no matter how wrong they may be. Otherwise, we would have whatever is the religion or belief of those in power being forced on the people. There are cases in history where Christianity was forced on people.
And there are cases where Christians were denied basic human rights, even killed, because the predominate view of those in power were either athiestic or anti-Christian. For the good of all in our modern western society, and after much blood spilled, we now reckognise that each person needs to have a basic human dignity and rights regardless of religion. This means that everyone is free to express their religion without fear of persecution and a recognition of basic human dignity and rights.
Today, much debate is ranging over how many people will die (I believe some already have) over the burning or non-burning of a religious text. If there was no religion, such outrages couldn't happen. I promote atheism for two reasons - 1) Truth IS important.
2) Religion has for centuries been a cause of (and bogus justification for) violence. Never forget that the 9/11 outrages were perpetrated IN THE NAME OF GOD. It does not matter which god.
Edit: You state that a girl from your class said that the heart could only have been designed by god. You ADMIT that it was a believer who initiated the discussion. Go figure.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.