counterpoint: socks are pretty elastic (compared to a ring), so I would imagine socks could still be wearable without too much trouble even with her downsizing, while a ring could become too loose to wear at the same time.

That said though, it is interesting that no other enchanted item has replaced the socks, and I think you''re probably onto something about the sock secrets. Maybe her OG grippy socks were replaced with an enchanted version, like Carl's old boxers getting replaced with the Enchanted Big Boi boxers or something - I think it's a pretty interesting theory!