There comes a moment in everyone's' life when they lose their partner to divorce or death. But the major blow comes when it's a mother who is left to manage small kids without her husband or partner.
Because whatever happens, whatever century we are in, single women are considered as opportunities for vile men to jump at them. And with the kids to manage, life goes from 100 to 10 within the day itself. Remarriage is also hard, because of the risk of having a 2nd husband who could abuse her kids.

The obstacle list goes on.
What obstacles do you know that single mothers go through in raising their kids?