I fly way TOO OFTEN, and always try to ship my knives & stones ahead of my journey as TSA
will invariably repackage your items poorly. I meticulously bubble-wrap & strategically place my tools interspersed throughout my clothing to cushion them further, but my bags are never returned as they were submitted... and they have been inspected EVERY time. In fact, I just got back from NYC a couple weeks ago, and they cracked a corner off my 8k Kitayama.
Not happy bout that, but it's to be expected sooner or later.
I have flown to France from the USA with knives, and Customs
is no different than TSA
... just another set of hands going through your bags & opening the knife boxes.. and they will.
It all comes down to if you're willing to ship them through mail with a claimed value under $50 for savings at customs on your side, or if you don't mind them being handled by TSA
in your Mother's baggage.
If it's just knives, I'd package them safely in her checked baggage, but shipping them as parcels in adequate bubble wrap is preferred.