No, Susan Boyle isn't married and has no children. There have been stories from time to time that she could be involved with someone, but they haven't come to anything and certainly there has never been any announcement or a proven story.

Until she suddenly became famous in 2009, Susan Boyle had lived a very quiet life. She lived with her family for most of her life, and for many years her main job was looking after her ill mother, who died in 2007. Before that, she had quite often sung in local talent shows and karaoke bars, and was well known in her area for her lovely voice. She even tried to produce a record in the 1990s. But she had never had a relationship, and after her mother's death she became very quiet and withdrawn for a while, giving up her singing and spending a lot of time at home with her cat.

You can see an overview of her life here.