Is she saying matt nails chip all the time, or your nails chip all the time?
If it's matt nails she's referring to, I'm not sure I agree, chipping isn't really related to product, it's down to poor client aftercare, or in some cases poorly applied product (too thick at free edge, insufficient capping at free edge, etc.)
If she's referring to your nails chipping then I'd go with her assessment, if she sees you regularly then she knows what will work for you day-to-day to trust her like you want your hair clients to trust you.
Remember, no-one posts pictures of their week/10 day/2 week old chipped, damaged, nasty nails, they only post pictures of them immediately after they are done so you won't see bad nails. Also the nails you see on Pinterest/Instagram/etc. are predominently bloggers or DIYers and are not expected to last 2/3 weeks that salon/everyday nails are expected to last by paying clients.