Its all about body language Ultraman - look for some subtle signs in the lady - this should be a giveaway if you finds you attractive.
She may touch her neck alot and show her neck to you in a certain pose,
She will play with her hair alot (called self grooming)
Genuine smiles - if its a genuine smile her eyes will smile back too (look for the creases or crow's feet to the lay person, if its a genuine beaming smile)
She may touch you alot subtly - i.e. on your arm which indicates that she wants you to touch her back
ALso - if you are sitting down together having a drink, watch for mirroring - take a sip of your drink if she follows and does the same - she is interested! Also if you notice she pushes her glass further towards your glass (your 'space') this is another give away that she is into you
Have fun!
RQ xx