From my experience and what has already been said, if your client has been to a true NSS salon, asked for gel or been told it was gel, she will have probably been getting MMA acrylic (liquid and powder).....ask her how they applied it.....did she have to put her hands into a uv lamp to cure the product when it had been applied.......not a nail dryer after the airbrush french was applied.
I'm sure she will remember having to put her hand into a lamp time after time and if she didn't that's a good indication that she doesn't have a gel application.
Regardless of all that, if the current product is sound, I would rebalance, although this might take you some time and a lot of files as the nails are generally as thick as your arm and as hard as hell to file.