I go to mainland China a lot, my wife and her family are from Beijing, so I'm not saying this as some kind of snob who happens to live in Hong Kong. Food in the mainland is fantastic, she is right, and it's much cheaper.
Ask her about the the fake baby milk formula and baby immunisation...
The hygiene standards in the UK are amongst the best in the world. Of course there are bad practices everywhere, but it's quite rare for the major players to fall below the expected standards.
You should see some of the stuff that is eaten in mainland China!