A single mother in my eyes is a mother taking care of the child by herself or with little help from the father.
My mom is a single mother, has been all my life. She works two jobs just to give me everything I want and more, I love her to death for it. She puts my needs before hers, she thinks of me before her, and she takes care of others before of herself, like the ones that come in to her job, her co-workers, or just people that she sees in need. I am not saying every single parent does/needs to do that, but that's how the single mother in my eyes/life is. There is also the single fathers as well, who take care of the children without the mother, and both should be recognized.