Bite the bullet, take the advice given here, block her number. Some people are users, you don't owe her anything and you've said it yourself "I find her uncomfortable to be around" and what a cheek telling you to get a job when you've had to take early retirement. No you don't need any of this in your life. I do hate invites for coffee when that's a front for something else entirely, once for me such an invite turned into an invitation to buy some goods from a little business the woman had and a request "would you like to start selling these products with me" I beat a hasty retreat. For you a request for help with Spring cleaning, unbelievable! You have to knock it on the head it will get worse, you are certainly not being unreasonable. Extricate yourself asap, If you run into her tell her why, "you feel harassed by the knocking on the door also," and anyway given she's had the damn nerve to tell you you're boring, maybe add "go and find someone who you don't find boring"
I wish you well, good luck, I do hope you sort it out and go back to enjoying your life before this gate crasher arrived.