Did several impressions, most notably Mrs Thatcher.
RIP Janet Brown
The widow of Peter Butterworth. I'm only vaguely familiar with her, but always a sad loss.
You're too young mate - she was a regular on TV back in the day but I'd never have believed she was 87. Sad loss.
87 
The was the most famous female impressionist of her day. What a shame.
Most under-30s are probably likely to know her for playing the Iron Lady in For Your Eyes Only
Sad news 
I Remember she was on Blankety Blank a lot
I managed to corner her at some Pinewood event a few years back. She was trying to slip out quietly so she could pop home and watch herself on Midsomer Murders, the sneaky old minx. Anyway, top lady, and true to form I have a record for every occasion. The single from this earned her an appearance on Top of the Pops back in 1979!
Yes, 87 surprised me. Some of her TV impressions in the Yarwood days made me wince a bit, but her Thatcher was spot on, she could have been her sister. I believe the two got on very well, and JB was an admirer herself.
Thatcher did a fair bit for female comedy, unintentionally perhaps, but JB was one of several women that did very well out of doing Thatcher. Thatcher didn't like everyone who used her in their act, I think she hated the lefty Sayles/Eltons for being too political, and grumbled at Spitting Image for its Tory bashing. So what she did was pick her favourite comedians to promote, JB, Marti Caine, Bob Monkhouse, The Two Ronnies, Paul Daniels for some reason and one or two others.
Dead! I remember watching her on the show 'Who Do You Do' back in the 70s but now, alas, no more. Very sad news indeed. http://www.bbc.co.uk/news/entertainment-arts-13582120