I find it crazy that someone still in 2021 - even if it's the grandparent generation - is trying to insist that left-handed children should use their right hand, "like normal children does".
My family (as in me, my wife and my children) is all right-handed, but my mother (and her mother) is left-handed, so I got some perspectives on that quite early on. Like my mother cursing because quite some scissors and other kitchen-utensils were optimized for being used by right-handed people. When she was a child (born 1955 - she was a young mother), she was forced into using the right hand "as normal children does" at school. From a positive perspective, this has caused her to be quite good at using the "wrong" hand, even to the point that she can write with both hands at once. (I've also tried practicing a bit, using chopsticks in both hands).