I think you are describing 'free edge seperation' - this is down to a few things, client aftercare, she needs to be using Solar Oil to keep the nails in good condition, dry nails can start to buckle as they gain length, this causes them to pull away from the overlay (gel or L&P) and cause this seperation.
It can also be an issue with application, you need to make sure your product is fully adhered all over the nail, it's easy to get carried away with Zone 2 stress points, and disappearing product in Zone 3, and you forget your free-edge. It needs to be capped to ensure a total seal and adhesion.
If left uncorrected your client could start experiencing 'greenies' and natural nail damage as it's pulling away from the overlay it could be taking layers of nail plate too, plus clients are naughty and she's probably fiddling with it and making it worse too. You need to remove the overlay or buff off any lifting to a solid place, and replace.
