I would not write her off completely as her ability can be very powerful in an item based combo deck, but she is likely just too slow to make an impact
Sure, we have Snow White, who hailed from the first ever feature length, cel-animated movie, Snow White and the Seven Dwarfs, but its not as if Disney created Snow White themselves
The ability to ink the card makes it hard for it to ever become dead weight, making it a strong option to include in any Steel deck
A Ruby card with a 5 Ink cost, Donald Duck is also a Floodborn character, so he can be Shifted into play for just 4 Ink
Real board control tool in Under the Sea
In the case of Vanellope, she reduces the Strength of all opposing characters by 1, for one turn, every time you play another Princess character