This summer I have had three friends apply for visas in the UK. One has been successful, two have not been successful. What seems to be different about the UK visa process compared to Japan (which is the only other experience I have had) is really striking. In Japan, you apply for your visa at the office. There is no extra charge for doing this and when you apply, the agent will check everything you have and not accept the application if it is missing something.
In the UK, you send your money and your application by mail to the office, with your passport. There is very little instruction about what is acceptable as far as documentation goes. The Home Office immediately takes your money and if there is a problem with your documentation, rejects the application while retaining the fee. If you are able to re-apply, you can do so at like a 25% rate, but you must start again, from the beginning. The website is awful. The people, when you call and if you can get through, are not helpful. There is no clear guidance and it's about 5 times more expensive than the Japanese visa.
My one friend who is trying to get married to a foreigner had their application rejected. So now what? You can't live together? I live under this fear constantly because Yoko and I being together with our kids will always be dependent upon at least one of us getting a visa in another country. And that scares the hell out of me. Makes me want to pack it all up, move back to Japan, and get permanent residency.
So we'll see if little Mei's application is accepted or not. At least they won't deport her. Or at least I don't think they'll deport her...