Just throwing this out there for people's thoughts, is it possible she went to take everything she needed to dispose of, including the dehydrator, right after the lunch, not knowing until she got there that she would have to make an advance payment to dispose of that one thing, so she dumped its box and a bag of utensils/plates/cutlery, and had to take the dehydrator back home on that occasion?
I think she didn't dispose of the dehydrator before the lunch in case her plan went awry, say they went moldy or she spilled them, or no one turned up, and she needed to use the machine again.
Then when she had to make a payment she thought about how she could do it without leaving a record, and decided to wipe and ditch her phone IF she was investigated, maybe not thinking that the tip would be investigated by police?