Thankfully, I've never had a cat that wanted to be on the counters and I've had cats for 30 years. I have friends who's cats get on the counter, and they don't mind. I WOULD mind! LOL! Since blocking didn't help, I would try covering the counter with something that the cat wouldn't like ... like double-sided sticky tape in random places?

She may be looking for a cool place to lay since counters are usually nice and cool.

We took in a stray Maine Coon this spring and he would spend a lot of time trying to find the coolest spot in the house (not that we keep our house that warm!). I searched the web and the bed that buyers suggested for keeping pets cool (especially dogs) was a raised bed. So, you may want to try one of these:

From the moment I set it up he climbed on it and now it's the only spot he chooses to sleep. Second best is outside in the cat kennel. It's also great for pets that are elderly or have difficulty getting up since that can just slide, or step off, the bed. No more struggling to get up from the floor.

Foil. I've used it to deter cats off the counter and it usually worked. One of our cats is very persistent when it comes to getting what he wants, so we had to go extreme and bought a couple of those Pssst cans of air with a movement sensor on them. It was so hilarious to see him jump when the stepped in front of the can. I still laugh, but it worked, it's very seldom we ever find hints that he's snuck up there.

ETA: Annz, that's a very clever idea. He's a very handsome boy and looks so happy there. (I had a cat that looked just like him. She was my sweetheart but passed from cancer a few years ago. Had her 19 years and I still miss her).

Loops of scotch tape where you think her feet will land on the counter?