Yes, she can be spayed anytime. It has many many benefits besides just keeping her from wandering, also. Spaying reduces the risks of certain types of cancer, prevents pyometra a very serious infection, keeps her body from being in stress from going in and out of heat, and keeps her from becoming pregnant, which is also taxing on her body.
So you are making a very good decision!
Spaying can be done at 6 weeks old or 2 lbs! So she is good to go. Some vets are a bit old fashioned and insist on waiting until 6 months. Waiting is just silly because a cat can get out and get pregnant at 4 months of age. So why on earth would anyone wait until 6 months? If your vet won't do it now then find one who will. Having her spayed before her first heat is a great idea, doing so will greatly reduce her risk of getting cancers and disease when she is older.
Can anyone give me some hints so as how to convince my Dad to allow me to have Hades spayed? I've told my Mom she gave it a ok but my Dad might be against it, he does have some appreciation for cats since he took care of ferals during his kiddie days. But it seems Spaying might be a new thing for him and he may not look forward to it. Thanks!