According to the younger element of my family, Fabric is great.
It only reopened earlier this year, after being closed in 2016, allegedly because of the drug related deaths of two patrons.
It was infamous for the long lines of unlicensed cars and drivers, that lined Charterhouse Street, importuning all and sundry, with whispers of, "Taxi sir."
If you go to Fabric, avoid those guys like the plague, they charge what they think the punter will stand for, and if you have an out of town accent, that will raise the fare.
Very popular this, and quite close to my house, no idea how good it is, don't drink beer, mostly vodka.
Take her up the Oxo tower.
Also, the London Bridge Experience is an absolute must. Do it.
L.B.E may be good, but as a lifelong south London resident, I've never been interested, I figure that there's not much about Southwark that I don't already know, but I've heard a couple of bad reports about the place.
Don't take my word for it, check it out from the outside first, I think that it's £18 a pop, and you may have to book online for that.
The Maltby Street market (only open Fri-Sun) is excellent and not anywhere near as touristy as Borough, although they're quite close so you could do both.
Maltby Street market gets consistently good write-ups from the locals, including me, excellent food produce.