It all depends on the plane you fly and the ground crew who checks the plane. You can take 10 kg without weighing, but the bag should not be too big or too heavy. I once met a case where the plane was too small and the luggage I carried with me was very large, and I was finally forced to weigh it and check it in. Generally speaking, being slightly overweight is not a big problem. It's not a big problem to exceed 1kg, but I still suggest asking the airline. I remember that it was only 20kg in the northwestern United States and only 30kg in ANA. At that time, the fine would be too bad. Also, if there are not many passengers on the plane, you will be allowed to bring more things, but it all depends on the attitude of the ground crew when you get your boarding pass. You'll be fine if she relaxes a little. If it's serious, you can't escape, because the checked baggage is completely weighed and you can't escape.

Above, some personal experience, I hope I can help you.