Ah Jennie, this is where my much-loved 'innit?' comes into its own.
For example, "I was here all the time, innit?"
             "He's from London, innit?"
             "She's my sister innit?"

It stands in for 'wasn't I?', 'Isn't he?', 'Isn't she?' and a host of others. Just like the Noushi word 'Deh!"

I'm surprised and interested that this 'question to answer a question' is only heard in UK. I reckon it invites the listener to agree as a sort of "Do you see?" or "Do you understand?"
I would guess that it's more commonly heard in the London area, but I may be wrong!