Yes, hopefully she'll do a grand job. And as the author himself discovered, it's a fallacy to imagine that anybody can proofread. There are good psychological reasons why most ppl cannot proofread. One reason was suggested by the author himself - he's so familiar with his own text, his mind simply races ahead of his eyes, so he misses the clangers.
Another reason is that even when errors are encountered, they are 'corrected' at a subconscious level - like a sort of autocorrect - so again they are missed.
ANECDOTE: I once worked for an architectural practice, and word got around that I was a bit of a whizz at proofreading. One of the associates asked me to proofread his contribution to the practice rag. It was just one paragraph, so of course I agreed. I proofread it while standing in a queue at the bank. On returning to the office, I asked this associate if he checked his piece over before giving it to me.
He said he checked it over several times, and was therefore quite confident that it was error-free. So you can imagine his surprise when I informed him that I found no less than six typos, including a misspelling of the word 'building'!! He was shocked. Six bloopers in the space of a single paragraph, from a highly educated and qualified architect who apparently cannot even spell building.
But of course he could spell building. His brain simply supplied the missing letter. When I explained to him how he managed to miss all his mistakes, the penny dropped, and he cheered up a little. But it proves my point - proofreading requires a specific mental discipline that most of us don't have. You hafta stop your brain doing what it does naturally, and that's not as easy as you might think.
Ask the missus, who teaches English (among other subjects), but still hasta pass her literary efforts by me before sending them out. And yes, she makes plenty of mistakes too.