I stumbled upon this letter received from Nick Robinson following my visit to Pigotts. It is dated 23 January 1991. In it he makes mention of a recent visit ‘from Petra and 3 of her children (two of them grandparents!)’

Petra Tegetmeier was one of Gill’s daughters. She died in 1999.

There is an admirable obituary here from the London Independent

http://www.independent.co.uk/arts-entertainment/obituary-petra-tegetmeier-1045848.html