Dm has received a pizza delivery 3 times in the last week that she didn't order. After the second delivery she phoned the pizza company and the told he to choose a password so she wouldn't get anymore deliveries that she didn't order...until last night, same company and his bag was full of food. She didn't accept the order.
We have a feeling it is sil doing this as sil has been known to do this to her side of the family (and worse) and has made malicious accusations to the DWP regarding my benefits (unfortunately for her it back fired and we found out that we weren't claiming everything we were entitled to!)
We have confronted my db and told him to tell her to stop, of course he is denying it as sil is whiter than white and she wouldn't do that kind of thing!! 
short memory. She has also denyed it and then said she will get the police involved if these accusations continue even though we have only confronted db once and we stay out of her life as she is toxic. She likes to play the victim but the amount of stuff she has done to her family and our side we just don't believe it and would put our lives on it being her. Dm is disabled and doesn't see anyone else who has a "motive"
The first pizza happened after dm had a bit of a moan at db about something trivial.
I can't believe that I'm writing this post as the whole situation is absolutely fucking pathetic but I would be very grateful for any advice on whether this is harassment from sil.
Sorry for the long post and if you've got this far thank you for reading.
Any help would be appreciated.