Hi, I'm looking after a small dog atm for neighbours who are away for a few days too. I'm an experienced dog walker/sitter.
So firstly it's way too hot to do anything with dogs during the day atm, due to the fact they cannot cool down the way we do.
So do not take out in car or walks whilst it's over 24 degrees.
I would get an old towell and wet it with cold water and place somewhere on your kitchen floor in the shade if you can, so that the dog can cool down.
Or you could spray with the hose to cool her down.
She might also just be too hot hence not eating or drinking much but important water is available to her.
Windows best closed in the day and blinds down.
Open windows at night to cool a house down.
You can google advice aswell, but tbh as long as you are keeping her cool, she'll be fine.