I'd like to throw another idea in. For very human-like waifus: Wheels are the way to go, but if she should have normal looking feet, then let's build her some kind of rolling boots. Like those for skiing, but less tight and with wheels on the bottom. Batteries included. She would only need to keep balance, but knowing how the contraption behaves is going to help with that. Also her ankle would be hold by the boot and she wouldn't need to move her arms or legs.
That aside, if they have good sensors in their feet we should be able to solve bipedal walking at some point anyways. Though, it hasn't the highest priority of course.