During the course of the Shifty investigation, the agency tries to get information on Shifty through his PA, Gemma. Initially assigned to Morris, Robin eventually decides to pull him from this line of inquiry when it appears to be a dead end.1 

However, Robin has better luck when she eventually takes on Gemma herself by “accidentally” running into her at The Vintry, a wine bar in the city.2

1: Troubled Blood, Chapter 15
2: Troubled Blood, Chapter  63