When the war really started to break out in their sixth year, the girls all created a plan. They would go into hiding in the muggle world, somewhere like London. Then Marlene fell in love with Dorcas, and she joined in on the plans to go into hiding. They all had muggle family whose lives would be at risk. Their own lives are at risk now, and this was the safest thing to do. That was until The Order came to be, and the headmaster decided to recruit a bunch of teenagers to fight the war. Marlene loved the idea, wanted to be on the front lines in the battle ground. Soon Dorcas decided she also did not want to just hide while their friends are out their fighting for all of their lives. Lily and Mary thought that more nameless deaths, as they would become if the joined the army, would not help anyone win. After that Marlene stopped talking to them as much, and soon after, so did Dorcas.
In late seventh year, Lily started dating James and with that Mary was left alone. Lily found out that James was also in the headmaster's army, and she decided to join. Saying to Mary how even if they did die, it is better then what will happen if the dark lord wins. Mary refused to even speak to Lily, because to her it wasn't. To her the means will never out way the cause if the mean are innocent kids dying.
After graduation, they all barley talked to her. She was invited to Lily and James' wedding, but decided against going. They were going to have a kid in the middle of a war that they were most likely going to lose, and no one thought twice about it. Plus the last time she spoke to anyone besides Lily, they all judged Mary. Judged her for not wanting to die for a bunch of people who have done nothing but discriminate against her.
When Marlene and Dorcas, then lily and James died, Mary could not stand it anymore. Exactly what she knew was going to happen, happened. Mary could not justify joining the war, but she could justify this. 'Maybe now i'll be happy, now that I don't know about the ghosts that haunt me' Mary thought as she brought the wand to her forehead, and she did not think twice before whispering that one word.