I created a Spring Wedding outfit for Arya based on events that happened in their life. In this particular phase: They're being wed to someone who they don't love as a matter of convenience and advantage. They're being forced to present as female which they are not. While their favorite flower is the Columbine, it's only used in the background as a representation of them taking the backseat to their own wedding.
Additionally, the flowers shown have dual meanings.
Calla Lilies: Often used in wedding boquets to represent purity and innocence but they are also the symbol for "death".
Columbines: Betrayal of lovers, infidelity