I have a unique perspective. I am a mom of a 6 and 10 year old and I am a gamer. I play every console and hav two high end gaming computers....
that said I would sell the Xbox and buy a switch even I had to kick in a little money to do it. The switch is portable, has mine craft, will get new games, and it has great kid friendly games like Mario kart etc. and your old child would probably like Zelda. It is said by many to be the best game ever made and it is appropriate for the young set.... dashing hero saves the princess from evil type. I have an Xbox one, PlayStation, wii, Wii U, switch.... and if I had to give up all but one of my consoles tomorrow..... I would hands down keep my switch.