Too young for a pen knife?

[HerondaleDucks]

Am I being totally unreasonable to say that 13 is too young to be given a pen knife?
My dp was talking about giving one to my 13 yo dsd.
I think it's too young, it can be construed as a weapon although legal at under 3 inch foldable blade, I don't think it's appropriate.
If she went to school with it she could get into serious trouble.
I also really worry about it potentially being used for self harm; her best friend self harms and as a reformed self harmed I'm conscious of all potential risks. She's not great at talking about her feelings and I know how easy it is at 13 to turn to methods of dealing with upset that are harmful.
I am a resident parent, so I do feel somewhat responsible about this choice. Dp thinks I'm over reacting, what does mumsnet think?

I would trust a 13yo with a penknife if you think she would like one (although not a 6yo!!).

Has she mentioned it though? Or is it just DH's idea? If she hasn't asked for one I would find it an unusual choice of present!

I should add that we are very outdoorsy people and go to the woods a lot, he uses it for carving sticks and doing forest school type activities