So she did not lie if she believed something was true.
A couple of years ago, my brother's spouse's family tree fell under the cool, critical eye of my mother, the compiler of family history.
She (the spouse) claimed woo-woo indian ancestry ever since we've known her. Her mother was the one that thought they had a woo-woo in their history, and so she took that at face value, and ran with it.
Suffice to say, after an exhaustive search, no trace, not even a jot or tittle of indian ancestry has been found in her line, anywhere. She continues to this day to deny the evidence clearly supporting the opposite of what she keeps telling people.
Elizabeth Warren once believed something, it turned out not be be true but still continues to insist she is of indian ancestry, even when all the evidence clearly states the opposite.
What was once possibly just an honest mistake has turned into a lie of omission, vesta. She may not have been lying about it in the past, but to continue down the path after all evidence points to the contrary is deliberate, and disingenuous.