My brother sat with my mother one day, meticulously recording every detail he could while she made a pie crust, filled it, and baked it. All the quantities, how they were combined, temperatures, durations, etc.
GP is pointlessly provocative, although an argument might be made that industrial pie production is neither art nor craft.
Your mom's case is different and much more interesting. She must make truly transcendent pies.
My half-dozen forays into making "from scratch" pie crust and filling have been surprisingly successful, but I might be missing something. I followed recipes from either Mark Bittman or America's Test Kitchen.
He still cannot replicate her pies.