Highly implausible that Chelsea Clinton ever made any such statement. Using a tweat by 'DiedSuddenly' makes it even more improbable that your claim is any more than blatant disinformation.
Such a statement by a well known, high profile personality would surely generate widespread media attention but no evidence of this in main media sources seems to exist.
If you advise where and when her statement was supposedly made it would make it a lot easier to find what, if anything, she actually said. Until then it can be regarded as unverified nonsense.
