Read "The World Without Us." A different solution would be to just have 1 child then get 'fixed.' If each woman had only one child the global population would decrease to tolerable levels within our lifetime, naturally. After a few hundred years women could start having 2 children each which would keep the population at a fixed level that the earth would be able to sustain.
She's not a 'hero' any more than people who have children are 'evil.' It's we as a society that are evil, we refuse to control our population and eventually it WILL catch up with us. When it does it will result in millions or horrible deaths all of which could be prevented is we (as a society) took some preventative action.