has nothing to do with being single, married, or in a long-term committed relationship. Also doesn't matter if you are a mother or father. Either you're a good parent or a bad parent.
Good parents: show their children affection, read to them and teach them, show them right and wrong through words and behavior, encourage them to do well in school, do not spoil them with gifts/money/excess, bring them up with values (religious or morals), teach them to respect themselves and others, teach them good hygiene, teach them the value of money and hard work... really basic stuff that a lot of people skip when raising their kids and we all have to suffer for it