in general parasites should be dealt with before any problems occur, as when you see that frog is sick it may be too late.
in a wild all frogs have parasite load, meaning they have the whole population of different parasites. In a healthy, normal frog in a wild those parasites do not present a problem, because the frog is adapted to them, a frog is compensating parasite infestation.

the problem appears when such a frog is brought in captivity and live in secluded enclosure. The transition process is stressful for a frog, thus its defenses are going down, but worms are still here and present a problem now. For some frogs added stress is not enough to diminish it's adaptability to parasites, thus they're still there but you still see a healthy frog, for now.
as time goes by parasites produce tons of eggs and offsprings, those are keep accumulating in the enclosure and re-infesting a frog until the population of parasites will reach massive amounts that a frog can't adapt to and you will see a sick frog.
that is with wild caught individuals, now imagine such parasites will infest captive bred frog that have zero adaptability....

fenbendazole ( panacur) is known for being relatively safe, accurate dosage is recommended for frogs.

You need to set up a hospital set up, moist papertowels and a cheap hide of some sorts that you can throw out after, paper towels have to be changed every single day, everything that you have in current enclosure you have to bleach out if possible, if not - it should go to the garbage.
hospital set up needs to be completely disinfected after a few days of starting treatment and repeated a few days after the second dose, a fecal exam should be done a week or so after second dose to make sure a frog is parasites free and can be placed in his permanent home.
I just wrote about parasitic diseases in other thread, coping it here you can refer for hospital set up suggestions. Antibiotics are not used to help with immunity, they work only against bacterial infections. if vet gave her a shot of antibiotics it seems to be too aggressive treatment for one "red spot" i would rather treat it with topical antibiotics if swap is positive for bacteria.

MBD - yes progression can be stopped with proper treatment that seems you're getting. not reversible is when you actually see bone deformations and open mouth, in your case it seems she has weak legs only, this can be fixed with luck. the question is on whys, why she got MBD? was it because her food wasn't supplemented or was it because she got supplemented food but couldn't properly absorb it, prognosis will depend on those reasons.
I would add 5.0 UVB if you don't have it already, provided she'll still have somewhere to hide if she chooses to.