Betty,
I’ve read a half-dozen or so of Rosemary Sutcliff’s books. They are mostly OK, with the following caveats:
The two retellings of the Iliad and the Odyssey have of course the expected mythological content, and the pictures are intense
The main body of her books (like The Shining Company, Lantern Bearers, Eagle of the Ninth etc.) are pretty much OK–well-written, very involving. There is quite a lot of violence and they are intense. If you have a very sensitive child it might be a difficulty. Slavery, injuries, battle scenes, being a galley slave–that sort of thing. My kids cut their teeth on Tolkien and have had no problems, my 12 and 14yo’s have read them, but I haven’t given one to a 10yo or younger yet. They really are good writing–they make me feel like I know what Roman Britain must have been like.
I would NOT give her retelling of the Arthur myth to a child. It is called, let me see, Sword at Sunset. Keep that one back. The rest are OK for at least 12ish up unless you have very sensitive children.
Michelle D