It could be caused by a few different things...
Often, stress causes their immune system to weaken and this allows opportunistic infections to sneak in.
It could be from contamination from the substrate, plants, water dish, or human contact, from a stress-induced infection, improper humidity or temperature, insect bites, injuries from plants or tank decor, contamination from other frogs, etc. Any number of things.
It does not necessarily mean you did anything wrong.
The best thing to do is to start a hospital tank. A 10 gallon is fine. Use only paper towel substrate. Be sure to rinse the water dish daily. Use only dechlorinated water or spring water. Cover 3 sides of the tank. Keep the temp around 78 to 80 degrees and the humidity at 70 to 80 %. You will have to cover part of the screen top if its a normal 10 gallon aquarium, to keep the humidity stable. You can turn the tank vertical if you have a way to keep the screen top on. You can even tie it on with two tight ribbons. Use a smooth glass bowl for feedings so there are no crickets to bite at her.
It's a bit pricey for a hospital tank, but I keep on hand a 12x12x18" zoo med for just this purpose.
Be sure to wash your hands and rinse thoroughly before handling her. You can use non-powdered gloves if needed. I use latex-free. Try to minimize handling of her as much as possible.
Keep her in a calm and quiet room. Continue her day/night schedule as you were.
You can heal her.
Dr.Frye is my vet also and he has helped me heal 5 of my adopted sick frogs. If you are willing to pay for the medicines, she will heal faster than using the neosporin. He had me treat mine with Metronidizole and SSD cream. Mine were very sick and also needed force fed and hydration soaks. I did also heal one frog on neosporin before i met Dr .Frye. They are all doing well.
I'll check back tomorrow to see how she is doing.
If you have other frogs, be careful not to cross-contaminate them. Wash carefully between them.
Good luck!