That involves the single parent utilizing a multitude of resources available from family, friends, neighbors, and community. It takes a village to raise a child.
While I do agree with that statement somewhat, there are those of us who've raised a child on our own, completely. My parents lived 4 hours away, and with no-one else really available to help, I had nobody to rely on. My daughter was 5 when I married, and she has turned out just fine.
Nos, in my neighbourhood, there are mostly families with a step-parent. In my youngest son's class, there are maybe one quarter of the kids, who come from two-parent families. Most are step-families, and a few single parent families.