"I understand that, it's the "every cell" aspect that I am questioning."
Actually, Steve, that's hyperbole. The doctrine of the Real Presence doesn't include that sort of detail. It's true that the Eucharist breaks down and assimilates into the body, as with natural food, which I think is what she meant, but strictly spealing, the Real Presence of Christ in a given host ceases when there no longer remains the physical characteristics of bread.
BTW, awhile back we ran a article on the general question of the Eucharist called "Is This God?" in
Envoy Magazine. You might find it interesting. You can read it here:
Envoy Magazine: "Is This God?"