I believe that all cats should be indoors only.
The only time a cat should be let outdoors is it you have a cat run, an enclosed veranda or alike.
I have seen too many cats dead on the road - just today I saw a black and white cat on the side of the road near my boyfriends house..poor thing.
Also cats are incredibly good hunters, and if let out they will hurt and kill small animals. Only letting them out during daylight hours will decrease the chance of them killing other animals, but it certainly won't stop it.
Feral cats have become a major threat to Australian wildlife. Although your cat is domesticated, there is a chance it can become feral if let to run the streets.
http://www.environment.gov.au/biodiversity/invasive/publications/cat-factsheet.html
So yeah I would either just try and teach her that going outside is out of bounds. Or you can start trying to make time to take her for walks, and look at buying a large fully enclosed cage to put outside for her to go in for a few hours a day.