how can i determine a kittens age?

This is a picture of the little one I found her and now she is nice, clean, and smells good. We r keeping her and giving her love and a home.

Do u guys know how I can figure out her age? Or does she look a certain age?

What colour are her eyes?  All kittens have blue eyes to start with, and they start changing at 6 weeks or so.

Teeth can give a clue as well - my kitten was teething at 5 months which is about average.

http://www.cat-world.com.au/kitten-development

She's a very pretty kitten, you need to take her to the vets for a check-up, worming, and see if they think she is ready for her first shots.  Also check how early they will neuter her - before she starts calling is perfect so before 5 months.  Certainly before 6 months, if they insist on her being older or having a call first find another vet.