My Dog wont bring me a tennis ball when i am looking at her

what sorts of things have you tried? with mine i always make a huge fuss about it... Ben is the only dog i've had that wouldnt fetch.. he tries his best. he'll run to it and pounce on it, then scamper away without the stick or the ball,  acting like he performed the greatest trick in the world.

With teaching them from pups how to fetch i always start out with a rag or a stuffed animal. we play tug for a moment, i praise them any time they put their mouth on that item, let them chase it around, just out of their reach.. then throw it a short distance and try to get to it before they do... pretty soon they catch on the game, when i let them get it first i praise the heck out of them calling them to me. just like teaching anything else.. it takes time and repetition and heaps of praise or treats, which ever you prefer.

my moms collie wouldnt speak on command while facing you. in fact she wouldn't bark on command at all. then one day when i was working with my JRT pup i said "Speak Amber!" and from behind me, Maggie, the collie said 'RUFF!'
 i turned around to Maggie and said "Speak!" .... nothing... so i turned back around to Amber and said Speak! ... and Maggie said RUFF again..

so figure that one out if you can lol  Maggie was just an odd dog all the way around..

In dog language, looking straight-on, eye-to-eye at a dog is considered a confrontation. Looking away, to the side, is a sign that says something like, "Don't mind me, I'm no threat, I won't hurt you!" Your dog is probably intimidated by you looking at her directly. Approaching someone head-on is also a sign of confrontation in dog language, so to your dog, if you looked straight at her and then she walked straight up to you it would be escalating the "confrontation" and making her feel uncomfortable.

Try turning your body to the side and patting the ground next to you when you want her to come. Look at the ground where you're patting instead of looking straight at her and see if she's more receptive.

I highly recommend the book "Calming Signals" by Turid Rugaas - it's really helpful for learning about dog body language.

if i look striaght at her and call her she comes, she Just does not bring me the ball. I had a dog in High School and it wouldnt bring something cause it wanted me the chase him. 

 Once my dog took a piece of wood from some people working own a house so the contrustion people would chase him

 Similar to the tug suggestion above, you might want to try handing her the ball first.  Let her get used to taking it from you in her mouth and then trade for a treat.  You could even add the drop it command once she gets the hang of giving the ball back in exchange for the treat----then just work backward from there--tossing it out a bit further and further as she becomes accustomed to bringing it back. 

thats another thing, like silver just mentioned.. i also read it in an OLD training book for retrievers... hand her the ball, when her mouth touches it, or if she comes into contact with it at all just praise! praise! praise!  of course in the book they were referring to a bumper - a floating training tool for retrievers -

i think it sounds like she is being somewhat submissive. its typical with dominant dogs playing with more submissive dogs. head is down, tail wagging, ears back... it looks like you own a more primitive breed so you're probably going to get more  "wolf-like" signals and reactions from her. what always helped me in training was reading about wolf behaviour and how they interact with one another. like Cita pointed out, you should read the Calming Signals book. it would probably help out a lot during play..... and play for dogs isnt quite the same as it is for kids, or kittens. i've seen fights, all out bloody battles spring from innocent games of tug and fetch between dogs. sometimes you learn the hard way... if i had known then what i know NOW i could have prevented such a confrontation with my own dogs.