"Friends and major donors insist that Mrs. Clinton is sincere in expressing ambivalence about seeking the presidency again..."

"... and they go so far as to assert that she is simply happy to have time to clean out her closets for the first time in decades."

Sincere... Clinton sincere... depends on what the meaning of sincere is.

The releveant OED definition of "sincere" is "Characterized by the absence of all dissimulation or pretence; honest, straightforward." Referring to persons, the word in English goes back to 1539, and the (unlinkable) OED has a lot of historican examples, but one stands out:

1824   Byron Don Juan: Canto XVI xcvii. 112   For surely they're sincerest, Who are strongly acted on by what is nearest.

In context:

So well she acted all and every part
By turns — with that vivacious versatility,
Which many people take for want of heart.
They err — 't is merely what is call'd mobility,
A thing of temperament and not of art,
Though seeming so, from its supposed facility;
And false — though true; for surely they're sincerest
Who are strongly acted on by what is nearest.

Right now, the closets are most near/To clean them must be quite sincere.

Ada Lovelace, the daughter of the poet Lord Byron, was the first computer programmer.

The Countess of Lovelace is celebrated today on her 197th birthday with a Google doodle and blog post:

After a chance encounter when aged 17, Ada became friends with Charles Babbage and grew fascinated by his idea to build an “Analytical Engine.”...

While Babbage saw it as a mathematical calculator, Ada understood it had much more potential. She realised it was, in essence, a machine that could manipulate symbols in accordance with defined rules, and—crucially—that there was no reason the symbols had to represent only numbers and equations.

“The Analytical Engine weaves algebraic patterns just as the Jacquard loom weaves flowers and leaves.” Ada Lovelace, 1843

As Ada eloquently argued, such a device could do far more than mathematics. She even mused about its potential to compose music:

“Supposing, for instance, that the fundamental relations of pitched sounds in the science of harmony and of musical composition were susceptible of such expression and adaptations, the engine might compose elaborate and scientific pieces of music of any degree of complexity or extent.”