The time to remove hair is when it becomes a social impediment to the child. We remove hair for social reasons, no other. If she's embarrassed to wear certain clothing because she does not want the hair to be seen, then it's time to teach her how to remove it.
I never cared about my body hair until I was ten and wearing shorts one day in fifth grade. At that time a popular girl in my class pointed to my legs and made fun of my shining blonde leg hairs. She covered her eyes and said the sun reflecting off of them was blinding her and to please learn to shave as soon as possible. Of course, she and her posse were clean shaven. They all laughed and pointed. Drawing attention to my legs so that others who were nearby craned their necks to see what the fuss was about.
Mortified, I tried to pull my shorts lower but I could not hide my shimmering leg hairs. Directly after school I cried to my mother, "Oh please let me shave my legs, the girls are making fun of me!"
And my mother said, "Oh poo. Who cares what they think. You're too young to have to worry about shaving and your hair is so light you can't even notice it."
Later that night I swiped her razor and a can of shaving cream. I locked myself in the bathroom and lathered up. I then proceeded to cut a huge gash in my achilles tendon because I had no idea what the flark I was doing.
Good lord that hurt and it makes my toes curl just to remember it. Long story short; if your daughter is concerned about it, please oh please help her solve her issue instead of letting her try and figure it out on her own.