Neil the key to posing on PHA is knowing when to reveal results.
Everyone's bored now- what happened???
tit

I checked the river and she checked behind me saying "well I did have it" and flipped

Maybe a bet on the river would have taken it.
Neil, I really think you did the right thing by checking it. For it to be right to turn our hand into a massive bluff, we need two things to be right:
1) We need the lady to have a very specific hand range- either a set or a flopped baby flush. If she instead has a big club in her hand, we are automatically gone.
2) I think it's a tough demand to rely on any poker player to find the discipline to fold a big hand. How many times have you seen someone scratch their head, think they are beat, but reflect on the pot size and the unfairness of having their baby flush "cracked," and make the call. I think your tournament would have come to a horrible end, with her looking dejected, saying "you must have a big flush?" and putting her chips over the line.
The previous pot has shown that you just cannot put any faith in this lady to fold
any hand, never mind one that was so big. In the pot where she made a call that could not possibly be good, she did not look disappointed with herself, but made a comment completely oblivious to the possibility of folding. Relying on someone with no poker ability to realise that we are representing a flush is like telling a lie to a deaf person.
I think you actually don't have a great representation for the flush even against a thinking player, for the reason that the river is the
king of clubs. If your calls on the flop and turn really were with a drawing hand, surely this is the card you are meant to have?