Rob72

Probably the easiest "tell" for seizure activity, whether absence or GTC, is the pain response. Use a Bic pen (tail or cap), and press it forcefully into the cuticle area of a fingernail. If they withdraw, they're faking. If they are playing GTC (generalized tonic clonic) with flopping, shaking and foaming at the mouth, they may continue with this, but the limb receiving pain will be rigid, attempting to minimize manipulation which would cause more pain.
For an absence seizure (staring spell) you can flick at their eyes, and they won't blink. Again, risky in that they may alleged that you hurt them, they may injure you, using sx activity as an excuse, etc..
I say this with the obvious caveat that you may have someone take a swing at you, and say they were, "out of it". Either get a CO to do it for you, do it only under very controlled circumstances, or just let them flop(probably safest).
For your experience level, and being female, I would probably simply say that if they display a post-ictal state, they had the real thing(confusion, discoordination, lethargy). Anything else is faker-faker.