How to let down a sort of friend

How do I stop somebody from inviting herself to my town for annual holidays? I don't want to upset her, she doesn't have many friends, but she's such hard work. We have hardly anything in common since I came back to my faith and her visits are so intrusive. She eats huge amounts and expects company while she eats, she tells the same stories over and over again (a side effect of loneliness possibly) my son can't bear her company and I get no peace. She literally just starts talking about how excited she is and she's booking her holiday, then she's over for a couple of weeks.

The thing is, I don't like her, and I feel guilty. My son doesn't like her and he has to put up with her too. Her main crime is she's boring and entitled. (I will delete this when I get some answers. I don't want to hurt her feelings by this ever getting back to her.)