I would take her to a vet as soon as you can. Do you know if your frog is wild caught or captive bred? The only things I can think of would be a bite from a cricket which isn't that common but possible. Is there anything in the tank she could have poked herself on.?They do lunge pretty haphazardly as the go for the crickets. If she's wild caught then it opens up options of parasites or other issues. When you get a chance could you post a picture of the enclosure. And post temps and humidity that you are keeping her at.