"Will it look as terrible as I am predicting?"

Yes :-) Taking shortcuts like this rarely turn out well when gardening. Take the time to do it properly. Kill off all the weeds (use the method of your choice but for convenience and speed, I'd go with an herbicide). Rake to clear out all the debris. You can take the time to remove and replace the weed fabric - under the gravel is about the only place I'd recommend using - or leave what's there in place and add more gravel to cover fully and even things out.

Weeds will still appear from time to time, with or without the weed fabric so your friend will need to be diligent about getting on them as soon as they appear, not waiting until they start to take over.

Because you are adding more gravel, you may need to reset the pavers so they are at the correct level.

Ria P..I agree with you..

weed fabric covered with gravel created an undesirable result..wouldn't a second layer make it worse?..have you ever noticed all of the "free gravel if you remove" online?..I'd remove it or offer for free..I see the same ads for awhile.."free gravel" isn't a deal for the taker..in my opinion the owner wins if someone takes it..

Contrasting materials look great

I'd also give some consideration to artificial turf instead of stones.

The previous owners of my house did that, 3 times. It is awful. I have no good feelings toward any of the previous owners.