I remember watching Kat win a tight match against Amanda Elliott at Bath in 2008, the year Kat reached her career high ranking of 551. I got some nice photos of that match. She played on until August 2010 going out in the SF of a $10K in Holland. She is still only 22 so it is a puzzle why she hasn't appeared since.
A quick google search turned up this re: Georgie...
"Georgie joined the ACTA coaching team in summer 2011 whilst she was recovering from an injury that stopped her from competing on the WTA tour. Since then, she has grown her coaching role with us and now works throughout the week, offering bundles of enthusiasm to our Mini and Junior Academy players."
Kat Brown on the other hand seems to be back in Germany playing for Wahlstedt in their version of the British Tour/ County Champs. Judging by the photos on their website it looks like the same Katharina Brown (and she is half German):
Compare this from Jan 2012: http://tennis-wahlstedt.de/topspin/wp-content/uploads/2012/01/3R7R3175.jpg
With this from 2007: http://www.advantage-tennis.com/brown-katharina/707_2673.jpg