I can't even count all the red flags in that scenario. "Hey, I've already determined that you'll let me in, even if I'm not invited or welcome, for fear of appearing rude. Now I just need to know when you're alone and unprotected."
The part where he wanted to know if the dog was going to be there is really disturbing. You know--a dog that would presumably protect her if she were being attacked...
She should tell him that she's getting a Rottweiler and it will be in the house at all times.
The nature of these questions demonstrate that he does not have her best interests at heart. As wazzie pointed out, the question about the dog is especially disturbing. Why would he need to know where the dog is?
Considering that he does not have her best interests at heart, she does not need to worry about being "rude" to him. She should never ever let him in her house ever again, even if he does have his daughters with him (some sexual offenders do use children to get close to their victims). She should instruct her daughters to do the same.
If she decides to have this little talk with him, she should do so only in the presence of her boyfriend.
I agree with everyone here and appreciate the input. She was taken off-guard when he showed up and has been kicking herself (and mightily creeped out) about letting him in ever since. We had a neighbor-gal pow-wow and have worked out codes and strategies to send SOS's to each other if anything of the sort happens again and she has trouble getting rid of him. Her boyfriend is aware of the problem as well and we are all being just a little careful until we determine if he is just a sad sack lookin' for love in all the wrong places or, well, Ted Bundy.
Shotgun loaded and at attention next to bedside table. Note to self: Bear spray is expired...