Without being specific, is she still in friern barnet?
If you check out her reviews you'll see she has a pattern, she reminds me of Parmela/Jessica where services depend on mood and how she feels about you, I think Amina is a nice person (well atleast nice to me) but agreeing services before hand with her is a waste of time.
I agree with you, you're probably better off paying £10 extra and finding a better provider who looks just as good, if not more attractive. There are plenty in north london. But if you don't care about kissing for example then you'll find a few at £50-£60/30 mins with owo included.