You don't say your site is ad-free if you get paid for links. Especially inside the donations pitch.
I don't care if you take donations, have a paywall, or sell advertisements (the ballet does all three, and that's awesome). Just be honest.
A maxim I use when trying to establish honesty: If you write a sentence that a substantial number of readers are misinterpreting, it's usually fair to call it an inaccurate sentence. If it's knowingly left there, it's usually fair to call it dishonest. Exceptions would include technically difficult material.
Edit: In this case, both the group paying her (Amazon) and Wikipedia refer to affiliate links as ads. I haven't polled her general readership, but that's a reasonable proxy for how the terms "ad-free" and "affiliate links" are interpreted.
https://affiliate-program.amazon.com/ http://en.wikipedia.org/wiki/Affiliate_marketing