I think it really depends on the temperment of the dog. An easy going dog is probably the best canidate for this system. As others have pointed out, some dogs will take the shock. But also if your dog is fearful in any way(ie thunder, other loud noises, strange objects). Do NOT get this system. We've had friends whose dogs were entirely terrified to go outside when they implemented this system. But if your dog is confident and not too prey driven, then it might work for you!
Here's another option to consider though. What about getting a pen to put her in? Like one of those chain link enclosed ones? She'd be able to have a place to potty, a place to rest and it'd be bigger than a typical crate. She'd also be safe from other animals and there'd be no training on your part.