Is it normal to have spider veins as a teenager?

Yes very normal: Spider veins also , know as telangiectasias or thread veins commonly first appear in the teenage years. About 40% of female population are effected by some sort of vein issue from spider veins to varicose veins. Don't despair if they bother you they can be treated.

Not uncommon: As dr. Wright said, this is commonly seen. Hormonal changes with the onset of puberty will often cause some spider veins to appear. If spider veins run in the family, this will make it more likely. Being overweight can also contribute to their appearance, if that applies here.

Any Age.: Spider veins can occur at any age although I have not seen them in anyone younger than 9 years old. There is a strong hereditary component to them as well as hormonal changes that occur during puberty. For an occasional spider vein the best treatment would be to leave them alone. If there are extensive spiders, you may want to see a vein specialist.