All my customers Know, that if they put a for sale sign up, I will only do it if they are home.
I have been bitten to many times by doing a house with a for sale sign up, do the Job and they move out before they pay up, so now I'll do it if there home.
If I arrived at your property Tosh I would Have gone in and priced it up a little, just for the first clean aspect, as already mentioned she may have just moved in.
If you want to break into the area give her a call and opologise for not turning up as your work over run.
Then ask her about her previous w/c this will get you into the topic of just moved in, or we haven't seen him for months sort of thing, at least you will know what game she may be playing, then you can make your decision from there.
Just noticed your reply about STC, this isn't always the case with some estate agents.