I think it's healthy for her to want a hobby that is hers.

Ask her "how can I help you with that?" Let her ask you to join her in it. Maybe pick up a magazine about hiking and give it to her, "I saw this and thought of you." Be her partner, stand at her side on this.

M22,H45,W45 S21/18D12
Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.