I think she's sincerely confused about the difference between insurance, and prepayment.
Knowing Jerry personally, I know that he sincerely wants the best for both Palestinians and Jews.
"I'm just a hack," he says, sincerely, although I believe his self-effacement doubles as a cover.
When she shared this with Weintraub, he was “sincerely shocked,” Ketcham said.
“I sincerely hope this woman is flattened by a lorry,” prays another.
I sincerely trust the young man has not suffered a lifetime for the act.
"I wish I had your faith in people, Grace," said Emma sincerely.
"And it's lucky for me that 'King' Plummer is my friend," said Mr. Grayson, sincerely.
That is a great deal nowadays, and he loves you most sincerely.
"I don't believe Laura will ever be good for anything else," she said sincerely.
1530s, "pure, unmixed," from Middle French sincere (16c.), from Latin sincerus, of things, "whole, clean, pure, uninjured, unmixed," figuratively "sound, genuine, pure, true, candid, truthful," of uncertain origin. Ground sense seems to be "that which is not falsified." Meaning "free from pretense or falsehood" in English is from 1530s.
There has been a temptation to see the first element as Latin sine "without." But there is no etymological justification for the common story that the word means "without wax" (*sin cerae), which is dismissed out of hand by OED and others, and the stories invented to justify that folk etymology are even less plausible. Watkins has it as originally "of one growth" (i.e. "not hybrid, unmixed"), from PIE *sm-ke-ro-, from *sem- "one" (see same) + root of crescere "to grow" (see crescent).