Will it be weird to use king size headboard on a queen bed
Fitting a full size headboard on a queen bed
PVC.
Don't bother attaching the headboard to the frame, and don't attach it to the wall. Just make the headboard taller.
Remove the bottom collar or "feet" from the headboard. Measure the inside diameter of the brass tube "leg". Go to the hardware store and buy PVC pipe to fit up inside the leg (see link above). you won't even need to secure it in place as it will go all the way up to the first horizontal bolt in the frame. If the diameter of the leg is <3", you may need to buy a 10' section of PVC. If you don't have a saw at home, take the PVC pipe over to the wood molding isle at the hardware store and use the saw they have there to cut two pieces of the PVC to length you want.
The "foot" may actually fit back on the PVC, but even if it doesn't, the PVC won't scratch your floor and the mattress will keep it in place. Done.
More on reddit.com