boxer or a border collie they are fantastic!
From the point of a child, YES!!! from the point of an overworked adult, A DISASTER.
Boxers drool all over your clothes, furniture, and rugs. Border Collies are hyperactive and go crazy if they don’t get constant exercise and/or play. The border collie in particular is a working farm breed which can get neurotic on you if you don’t have enough space for them to “run off energy” every day.

And did I mention “dog smell?” :coolinoff:
Dogs are also expensive to keep, and the bigger, the more expensive. If you go away on holiday, you have to either take the dog with you (which restricts where you can stay) or pay someone to care for it while you are gone.
If you must have a dog, a small, quiet breed would be better-- research this, and don’t just get a dog because you like its looks. The “101 Dalmations” movie saw thousands of pitiful young Dalmations in animal shelters the year after that film was released, because families like the looks of the high-strung, active breed but did not learn about it to know that in too many cases, it was not the ideal family dog.

“A dog is for Life, --not just for Christmas.”
Children see fun, not long-term responsibility. (YOU will wind up as dog feeder, not matter what you hope) Sit down with them with the economics of money spent on a dog-- food, vet bills, boarding expenses-- for 15 years or so, --which cannot be spent on others things they will want in the future. Talk about school trips and clothing and games they will have to sacrifice. Talk about your rent / utilities / transportation expenses, compared to your ACTUAL INCOME. This is a good way to introduce them to adult thinking.
My mother and her 5 siblings grew up in the Great Depression and begged their father for a dog, which he told them they could not afford. They brought home a stray anyway, and hid it in a shed. Though they were hungry themselves, they smuggled food off their plates for the dog, which slowly starved to death anyway. When they cried, their father gently told them that he knew they had the dog, but wanted them to learn first hand about the reality of not being able to afford a pet, and that parents had good reasons to say “No.”
Years later my mother got married and then got a cat which she loved and cared for all the better for having the earlier, sad experience with the dog the family could not afford.