I made the mistake of forming a definition of 'puppy proof' without the help of Red-Nose's girls, so it's going to need some re-working.
Duzz tested all the gaps in the baby gate and found that she could squeeze through the last one where it meets the wall. Instead of recognising that the sandstone block that forms my back step is too big to clamber up, she takes a run-up, a bounce step, and a flying leap inside. So for the moment my plans to contol her movements have come unstuck.
Luckily she has quite a bit of self-control for a tiny puppy. Having had her play time she is content to have her rest time, and she is voluntarily seeking out her crate for quiet times.