Some female panthers will start to produce a clutch even just by seeing a male in close proximity. She could be. The colors dont seem to scream out that shes gravid and its too early to tell by her size. Maybe let her see him through the cage. If she has started producing eggs, shell freak and display a dark brown to black coloring with some kind of orange within her flank and belly. If she stays a neutral, peachy color, and doesnt despise his presence, then she is probably receptive. Unfortunately, if she is already producing eggs, the clutch ill be infertile this time. In which case, youll have to wait untill the next receptive window opens. When eventually you do get the chance to introduce them for a breeding project, have a pair of gloves on hand in case one of them gets too aggressive and they have to be separated. Also be sure your female is good and healthy or she will more than likely die.
Keep in mind that laying eggs, fertile or not, is what your girl is meant to do. If she is healthy, there shouldnt be any problems.