Maybe look into somewhere like this? Prices in Euros and additional fees for cleaning and deposit but worth a look.
http://www.budgetplac...dget-apartments-list/
Depending on transport links then they could look further out if it is cheaper and it works out cheaper overall travel wise. Other alternatives like putting most of their stuff in storage and downsizing to something like a studio might also help cut costs.
Maybe she could have a word with local places to see if they could negotiate a deal for a longer stay but it would probably have to be quite definite booking wise so they can manage bookings Also the issue of food preparation and storage if they are staying in a hotel as money could rack up on having to buy food that doesn't need to be cooked or stored in a fridge.
Do they have any friends they could stay with in return for some rent if they can get a load of their stuff in storage?
Ps if they find hotels with kitchen facilities in the room make sure they look at them first to check them out - I had one booked for me and I'm not fussy but it was awful, dirty, smelly, damp and water running down the wall in the bathroom etc... and run by some creepy men.