Wow, sorry for your loss. Was she young or older? Did it look like she suffered any kind of injury? What you can do is take it to a herp vet and request a necropsy. Sometimes things are just out of our control when it comes to survivability of our animals. It happens to the best of them. Stay in peace and not pieces.
I agree on getting a necropsy done to see what happened to her. So sorry for your loss, it's hard enough losing a pet but even worse when it happens suddenly. Sending lots of love and comfort ️ stay strong.