OD = more stressful on the kidneys/liver may not be an issue for a one-off, but keep an eye on the urates after - yellow urates would indicate liver/kidney stress - can go all the way up to a tumeric yellow if bad.
I know some painkillers effectiveness wanes with time, so perhaps the side effects as well, but couldn't say for sure. Not a vet myself and running off the knowledge I've accumulated helping at Birdcare once a week for the past year.
Would you be able to crush the remaining 2ml and split the powder down to 1.5ml then make a suspension with a bit of water to give via syringe? That might be the safest bet.
Since she's so wild, when you wrap her, tuck the towel under her wings before wrapping her body - tends to keep them from flapping out. It's a good trick I've picked up from Birdcare.
I do all my bumblefoot extractions over a running tap so I can keep the wound clear so I can see what I'm doing around any bleeding. Soaking the feet in a warm Epsom salts bath for at least 30 mins should help soften up the kernel for extraction. I use ceramic hooks for digging out infected tissue left behind once the kernel is removed.
When done, I pack the wound with betadine, pad thickly with non-stick gauze and wrap it up with vetwrap - two thin strips between the toes, over the gauze and up the leg, then one thick wrap around the thin ones around the leg to hold everything in place. - has worked good for me with no kickouts and keeps the wound dry and clean.