Barbara (portrayed by Miranda Hart) is a self employed cleaner who works under the business name of "Metropolitan Cleaning Services UK".
Following Kate returning to America Tim hired Metropolitan Cleaning Services UK to clean the flat in preparation for it to go onto the market for sale. However, Barbara also has an unfortunate habit of breaking things.
Why Lucy didn't sack Barbara is a bit of a mystery - she was more than a little clumsy, which isn't a great attribute for a cleaner to have. On the rare occassions Barbara did try and do her job, she almost always ended up breaking something.
Barbara was quite bold and confident... and most definitely not quite all there, preferring to spend time in her own world instead. Barbara was not afraid to stick her oar into domestic disputes should she happen to be loitering around nearby... which she invariably always was.
Although she is the managing director and CEO of the cleaning company she works for, it should be pointed out she is actually the only member of staff!
In series three, it is revealed that Lucy is planning on marrying Pavlov, a mechanic just so that he can stay in the country. Instead, Lee gets Barbara to marry him instead and so they drive off for their honeymoon in India.
Barbara isn't cleaning the flat any more - probably because she married Pavlov and lives with him now