In theory any pony can "burn" - that's something that should always be borne in mind and a good reason why when sun fading you should always check as regularly as possible. But it is also true that some ponies, those most prone to age marks and general plastic break down issues, will burn the worst.
I agree with TheLoveOfPonies, that white Tootsie is not one who I have heard or seen mention of having a particularly bad reaction.
Good luck!