I have a four month old german shepherd called Tess, shes a lovely wee
dog and her training is coming along well.
One problem I have and I hope someone out there can help me with, she
is very possesive of her frisby, she will bring it back but if I try to pick it
up she runs away with it, have tried treats and used two frisbies on the go
but shes a wake up to that trick.
Really to the stage of giving up on that game but we do have fun when
she is in a good mood to return with it.
Thanks in anticipation.

to me it sounds like you are the submissive party in her eyes. you need to be firmer with her and become the dominant party, using some simple exercises that you can do in your own home. you need to stand tall without being ridged and you need to relax at the same time. you must never back down to her and walk away, because in the dog world this means that you have submitted and backed off and she has again won. you need to always be calm and assertive when doing any exercise with your dog. you can practice dominance when out on walks. dont let her got out of the door in front of you and dont let her walk in front of you unless you give her the leway.

back to the frisbee:
some dogs get obcessive over toys like your dog with the frisbee. before you continue to play frisbee with her you can do another exercise on the lead in your garden or home, but with a twist. you can put the frisbee on the ground, and some other toys that are her favourite. they must be about a meter apart for this to work and for her to achieve in this exercise. once you have the toys in place, put some pebbles, rice, coins or anything you can think of that will fit in the bottle and rattle, in a small plastic bottle and put the lid on it. you then have got your startle tool, without this costing you anything. you can then put your dog on her lead and take her outside. make her sit and if she attempts to get close to or take the frisbee or toys then you must correct her with your bottle, shake it and she will stop and wonder what is going on, this will snap her out of the obsession for a small amount of time.
you can then walk her past the frisbee and the toys, but everytime she gets too close, looks at the toys or even tries to take it, then you must firmly shake the bottle. when you shake the bottle, you must say leave it everytime for this to work. this will take time, but will be very effective. if she leaves the toy and walks past it, praise her and give her a treat. you can walk her up and down past the toys for as long as you like but you must correct her everytime she pushes her luck.
she will soon learn leave it and will then start to avoid the toys when you walk her past them, you will also notice that she will be more focused on you and the walk, not the toys. when you are at this stage you can reward her with love and a treat.

now for the next part:
if you have done the exercises right she will now respect you as the pack leader and listen to you more, when you tell her what to do or not to do.
now you can play with her and through the frisbee for her, when she brings it back to you and puts it down, you need to stand tall, keep calm and assertive and step forward, tell her to leave it. if your training has been successful then she will back off, if she does this then you can pick up the frisbee and reward her with a treat and continue playing without the annoyance of her not giving it to you.

i have used these techniques with previous dogs and they work, as long as you are patient and take the time to train her in this way.
if you need any more help then please feel free to contact me

Thank you so much for your very good hints on Tess's problems I had just
about given up.
I will get straight on to it.
Thanks again

if you need any other help during training her then please let me know and i will give you some tips and advice.

hope everything goes well during the new exercises with her