Education Tablet for 4 to 10 YO - Used Kindle Fire

Consider a micro USB magnetic charging adapter. They're quite low profile now. The adapter permanently occupies the charging port, and it's mating end lives on the charging cable.

The two ends are held together with magnets, so no mechanical torque will transfer to the port as the connection makes and breaks.

This won't help your existing broken tablet but will make a replacement last longer.