>>280793019
Mom was probably part of Garden.
>Axeman uses emblems for visual storytelling
>Yor has a rose emblem all over all her outfits, but especially her Thorn Princess one
>it is consistently absent from every single appearance of child Yor until her first mission as Thorn Princess
>mom wore the same emblem
Hemlock also recently made a comment about Yor not deserving the name Thorn Princess, which adds to the idea that it's inherited.
The fanbook posed the question of how Yor found Garden. Detailed instructions straight to them from a former member is a pretty clean explanation.