Connie Willis has written some good stuff; I've just finished reading "Blackout" and "All Clear", time travel stories set in the 1940s during the war.
There's a *lot* of detail about which buildings were hit and when, and the Dunkirk Evacuation, and the V1 and V2 blitz, and the VE-day celebrations, and rationing, and bomb shelters, and maybe that detail is correct. But ...
1) She thinks that Nelson's Column is called Nelson's Monument
2) She thinks that UK currency in the 1940s included two penny pieces - that didn't happen until decimalisation in the seventies
3) She thinks that you use tokens to get on the London Underground. No, that's New York. In London, you use a ticket, which you purchase with currency.
These are small details. But it means that she didn't get anyone from England to read her manuscript for howlers like this, and that, unfortunately, casts doubt on the accuracy of all the other details in her books.