I would recommend buying her a set of cheap pens and let her know that these are her pens and she is allowed to disassemble those, if she wants more sophisticated pens, then have her dome some things around the house to earn them.

Encourage the curiosity that is involved and couple that with a goal system in which work ethic can be introduced ... my 2 cents

DS9 - Starting 9th grade
DS7 - Starting 5th grade