Just thought I ought to let everybody know that we got 60 day 3 month single entry visas from the UK Chinese Embassy without too much bother-simply got a letter of invitation from our daughter and a photocopy of her passport to go with the applications. It may be that because (i) my wife is Chinese, and (ii) we have been many times before that we found it relatively easy,but my visa company (CIBT) told me not to expect any difficulty.
Hope this will encourage other potential travellers!