Totally agree with that Chorley, I found her the same on my one visit.
But has she ever got her tits out with you?
I think two reviews here had her doing that for extra when requested.
With this type of girl I think perhaps a level of trust needs to be built up, and before going further than usual, some gentle persuasion.
Having said that, as we know, she frequently has her other half (or whatever he is) in the house with her, and he does prowl around, much to her annoyance. This might also put her off.
Although of course as we know, Mei in Stevenage ended up fucking most of her regular clientele (my lucky self included).