"We were talking about that and walking back to the hotel arm in arm - a little bit merry - and we walked past a tattoo parlour.
"Before I knew it we were in there and we both got a couple of little stars. Thank God that's all we got. I've got them on my wrist and she's got them on her ankle."
Speaking about returning, French beamed: "Don't tell anyone in Australia, but New Zealand is my favourite place after Cornwall. I've been many times and I love it. I just want it to be moved closer to the UK."
Before she heads Downunder, French will work on a movie of TV comedy Absolutely Fabulous with Saunders, due for release next year.
"It's happening this very year," she said. "It started with Jennifer procrastinating for the best part of 10 years. I bet her 100,000 [$237,000] she wouldn't write the film, because she procrastinates so much. The following year, she handed the script to me. It's got Kate Moss in and starts filming in October."
French said she was "sick with excitement" about her visit and promised plenty of laughs.
"I love that I can't categorise it exactly. It's somewhere between a monologue, a play and an autobiographical slide show with a few funnies thrown in."
French will perform at the Isaac Theatre Royal, Christchurch, March 15-16, Wellington's Opera House, March 21- 22 and Auckland's Civic, March 29-30. Tickets from livenation.co.nz.