All of my pens are gifts. I try to tailor the pen to the recipient.
We don't know much about your niece or her interests. What are her favorite colors? Does she like modern, current stuff that's "in style"? Does like old school, traditional things? Will she be using the pen a lot? Carrying it around in a purse? At her desk? (If it is a desk, then think about giving a pen and pencil set.) I would start by asking myself questions like that.
Is there a special pen kit that matches her interests?
What message would you like to send? A piece of wood that grew in a far-away place (like Africa or South America)? Something that says, "USA"? Bethlehem olive wood? Ancient kauri wood that's 50,000 years old?
Truth be told, any handmade pen from Uncle Gabe will be a most appreciated and treasured gift.