According to that rucksack, she should have 50+ L of free inventory volume.
dumb question i know, but… is she actually WEARING it, or just holding it? did you GIVE it to her, or say ‘here use this.’
I don’t know, she had the rucksack before I met her.
All other NPCs also have 0.00L volume. That number only increases if I ask them to remove worn clothing. I can also give them items that they can place into storage, but not clothing.