Looks like each borrowed from the other. Snow White and the Seven Dwarfs came out in 1937, Children’s Fairyland opened in 1950, Disneyland opened in 1955.
As far as IP goes Disney would probably have a stronger claim (harder to argue “you can’t build a fairytale castle!” than “you can’t use our copyrighted character designs!”) but I’m glad Disney seems to have refrained from doing so.
