Just seen that I was asked a question which I hae failed to answer.
Re school reading books - I wouldn't really count that as "reading" in some ways. It's about decoding, rather than enjoyment of a shared language and culture. So I expect I will listen to my child read it as far as possible; help out wherever I can; and then discuss what's going on in French.
If the book is more complicated and the issue is actually enjoying the story and fostering a love of reading, then I don't know; but then I confess I don't really "get" why schools send home that sort of book anyway (okay, I do - some families might read "homework" books more readily than they would read for pleasure - but that's not us.)
Her French Saturday school actually does send books home. They're a bit simpler than what we read normally, but we do read them once or twice together, normally on the Saturday afternoon, then I'll read it again through the week if she likes it or, more likely, it just goes back next Saturday. I do all this reading; her mum doesn't attempt to read those books to her, in either English translation or French original.
Or, of course, she can read schoolbooks with her mother and I can focus more on maths (which her mum is rubbish at) and, the rest of the time, we can both read to her for pleasure.
I'll have to play it by ear when it comes up - tricky one.