Slippy ( by name slippy by nature
) you are not doing yourself any favors.
Things come back on you as you are finding out to your cost.
You say she's a bit mad, her dear old friends are looking out for her by the sounds of things. Then what does that make you ? an opportunist taking advantage ( possibly ).
Whether anybody has seen you producing pure water there or not isn't the issue here. Do you really want to be working under the radar that way, knowing what you are doing is without her consent or worried about prying eyes ?
I don't mean to sound harsh and any digs are meant with humor, but do things right.
I've been in a similar situation re getting a supply of water in order to work. Its difficult yes but not impossible. I had to run an ro out the window of my first floor flat to my street parked van for 7 + years. The only reason I don't anymore is because parking has become increasingly difficult and began dictating my working day and free time. I sourced a supply of ro water from another windy that I pay for.
Can you not do the same ?
Trying to save a few quid or obtaining water fraudulently is only going to end badly and leave you high and dry ( at the least ) without the means of being able to work.