As a sitter and independent contractor, you can set your own business policies. However, the service listed on Rover is House Sitting, which most customers would interpret as a person staying at their home and taking care of their pets, which would mean feeding them, walking them, etc. There is no service called Overnight Stays.
This service is subject the most varied interpretations on Rover, and I often see customers come onto this board to ask what it entails. Rover does define it as the same as boarding, in that each "night" is good for up to 24 hours of care for a pet. Some sitters move into the home and use it as a base of operations so they can walk other dogs or perform drop-ins. They come and go. Some even have full-time jobs or are students, but are able to check in on the pet during the day. However, some only come over in the evening and leave in the morning.
IMO House Sitting is a premium-type service and should be priced accordingly. If you feel that you are not getting enough to provide the pet with multiple walks per day, then I suggest you raise your rate. From a client standpoint, I would rather see an all-inclusive rate to being nickel and dimed for everything else.
Housesitting includes “taking care of the pet”, walks included. That is not unreasonable. The owner is already paying a fee.