It is obvious from the time Loki learns to walk that she is not going to be very good at it. Normal toddlers fall, and often; she does it more, and longer. She has been practicing at walking for years before she can cross a floor smoothly nine times of ten, even if she does not sprawl completely every time she missteps.
She winces when she trips, not so much out of embarrassment or because she's hurt herself, but because the reactions are never good.
"It should have been locked and warded so that none but Odin could pass it," says Frigg. "But even so, not all doors that you can pass are doors that you should."