Would your daughter be comfortable sitting on something without a back to to? If so you could easily fit the little vanity stool (can also be used as a footstool) that is at the desk inside.
Just a thought to save you from packing a chair.
BTW - if you are in a Cat. 7 which is a navigator veranda (my favorite) you will only have one chair and a padded bench. The bench could easily seat both an adult and a child.
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