... just being there for an hour of being wined and dined.
... its the biggest gift in all of the world as its being paid £40 for effectively nothing and no work basically.
If she genuinely likes you, doesn't find you boring, borish, too old, ignorant, ugly, a bit of a wanker etc. then she is getting paid to have fun.
Otherwise, she's working hard. Possibly a lot harder than lying on her back making the odd moan whilst thinking about her upcoming holiday because she actually has to engage with you rather than just following a script.