How do I tell her off without embarrassing her?

There is this woman who is pursuing me. She is much older than I am and is a mother of three children, the eldest being in Senior One. She recently started calling me daily, including late at night. I thought she was just being a good friend. I also thought that she was married. I only learnt later that she had separated from the father of her children. 

 

About two weeks ago, she told me she loved me. When I gave no response, she started claiming there was divine intervention and was convinced I was her husband no matter how much I delayed it.

 

She has started using underhand methods to get me and the more I dodge her, the harder she tries to get me. She has told my friends and family of our forthcoming wedding and I’m not planning to marry her. How do I tell her off without embarrassing her?

Francis Abura, Lira