OH MY GOD! Mate, I am blown away by that foot! I can't believe you're just concerned with the abscess when her foot(feet) are in that state! That you've not recognised how deformed it is. You need some SERIOUS help for her NOW! It's far & away out of the realm of a forum to give much advise of what to do in in a situation like this.
Interested to know how long she's had such profoundly damaged feet? How old is she? How is she managed & what fed? When was the last time she saw a farrier or vet(obviously not in recent months)?
I would be finding the best vet you can, who is experienced in serious hoof pathologies, getting x-rays and be prepared for potentially a lot of expense. Then the prognosis may be hopeful.