Hello Graham, I'm Dr. Deb.
I recently came online and see that your question about Franki hasn't been answered. I'm so sorry that you've had to wait for a response,but if you still need assistance, I'd like to help if I can.
First, let me say how sorry I am that Franki was diagnosed with cancer but I hope that she's recovering from her surgery.
The fact that no pain medication was dispensed is a mystery to me since this is standard procedure for many vets these days.
I would strongly encourage you to ask for either Tramadol or Gabapentin (both human drugs, readily available) when next you have an opportunity to do so.
In the meantime, I'd continue the Paracetamol (aka acetaminophen) but just be sure that it's not available to any cats if you have them (it can be quite toxic to them). The dose for this drug would be 10 mg/lb twice a day. For example, if Franki weighs 20 lbs, then her dose would be 1/2 of a 325 mg tablet at one dose.
This would be the best drug that would be available to you over the counter.
This drug may help if nothing else is available to you but it frequently isn't strong enough to help with significant pain. Tramadol and Gabapentin are better choices.
I hope this helps; again, my apologies for the delayed response. Deb