The 78-year-old, a passionate royalist, expressed her gratitude towards producers for combining Rita Sullivan's wedding with the Queen's Diamond Jubilee.
She told Inside Soap: "It's such a huge honour and I was overwhelmed - it makes me weep to think of it.
"A lot of television is geared towards kids now, so I think it's just brilliant that they've given older people a good storyline. It's so uplifting. And Dennis is the right man for Rita - at last."
The actress also praised Philip Lowrie, who plays Dennis Tanner, for being "such a gentleman" off screen.
"I love working with Philip Lowrie," Knox added. "The first day he filmed with me after all those years was incredible.
"I hadn't seen him at all in the meantime, but it was like coming home."
Lowrie, 75, appeared in the Weatherfield soap's first ever episode before bowing out in 1968.