I’m not sure if the pet sitter is coming to your house or your budgie is having his own little holiday at hers.
If he’s staying in your house it would be nice to get a timer plug and ask her to switch the radio/TV on when she leaves, and the timer set to switch it off later.
If he’s staying at hers, then don’t assume that she’s aware of current best practice - Check location to any other pets/ possible fumes etc.
I would also recommend you leave a check off list for her to view and work through e.g. a printed chart with dates down the first column and jobs along the top: remove top soiled layer of paper, wash water dish and replace, empty contents of seed bowl and replace with X quantity of Y, etc.
Same with your partner
Have a lovely holiday!