If she were mine id treat her now. As you say, could be the infection causing her sad symptoms (just happens she's also in moult.) so you could pamper her for a few days, but probably better to deal with foot, ASAP as if she doesn't improve you've lost time in the battle.
I would give it good clean. Then soak in warm saline, about 40'C, see if this opens the abcess to get pus out. Soak/wipe/pick scabs off. Ive used syringe with saline for flushing out pus, if you have one handy those capsules for rinsing eyes are so easy to use, and you can refil from cup of boiled sailine to keep flushing. Purple spray. Repeat couple times a day. I would also cover -with plaster. She may limp more after treatment. Should be lot less pus within a day. If bird not improved within tops 48hrs I would be after vet for antibiotics. This is just my opinion.