John - Given your description of your bitches symptoms and the response and results of vet's tests. I would not rule out pyometra, although without a discharge I think it unlikely (also a high temperature is usually seen with this).
More likely for me is the chance that following her collision with your other dog there is some form of skeletal injury or bruising that is resulting in her being quiet. The fact that she jumps about when there are visitors or when you got her home from the vets is just the endorphins kicking in and like most running dogs they can readily ignore even rather severe injuries when the adrenalin is flowing. If it was one of my lurchers I would be thinking in terms of resting her for four days at least with only lead walks for toilet breaks, and these to be kept as short as possible then if you are not happy and there seems to have been no progress, check with your vet and consider X-Ray for spinal/pelvic injury. Whatever the progress made, there should be no running for 14 days minimum. If you get someone she knows to walk her away from you and then back facing you, as you know your own dog best, you should be able to tell if there is any uneven gait or her favouring a limb - or even a slight twisting to her action. Any of which would indicate the presence of some skeletal injury. With a view to vets - is there a specialist running dog vet locally who you could visit for an opinion as they are animals that vary considerably from your run of the mill pet dog and although well meaning (obviously) a local vet may not have the degree of knowledge that is required. This really isn't as daft as it sounds - it is rather like taking an F1 motor car to your local garage.
Best of luck, hope she is soon well and that in some small way I may have been of help.

Gordon Hi, thank you for your response, Rosie has not had a high temp on any of the visits to the vets just up a tad and the vet said that could be the stress of the vets,
I only let her into the small back yard for her toilets,
She has had no discharge from the rear,
I will take your advice re exercise , I do have a feeling that there maybe a slight improvement during the last 2 hours,
She is now watching me as I move from room to room and pricking her ears and seems to be more aware of things,
I will keep you all informed on her progress,
Thanks again.

Just wanted to send get well wishes to Rosie.Such a worry when they're poorlie Hope she continues to improve and back to herself soon xx

Thanks Lacey,

Hi All,
I am pleased to say Rosie is a lot better today, she is eating well Chicken , scrambled egg, tripe, and some of her nuts'
She is also drinking water well,
Rosie has been following me around today and when I got Poppyseed lead to go wakies she even wanted to come,
She is not just laid in her bed looking depressed ,
I would like to thank you for your input as you lifted my spirits
When you were pretty confident she had not got Pyometra,
I will of course update you and thanks.

Hi John can I suggest a couple of things to help maintain the improvment.
To give things time to settle down fully (I think the collision caused some damage) only short walks for the next few days and absolutely no jumping up instead bend down to her... and no stairs...

I hope things continue to improve...

Thanks Meg, I will take your advice but she is not so well this morning she stands with her backend up in the air & front legs outstretched & she is all tensed up and quivering sometimes,
Not eaten much this morning so I am taking her for a second opinion to Medivet at oadby the have a specialist in acupuncture and the other vet has specialized in whippet injuries for a long time,
I will keep you all informed,
Regards John.

Sorry to hear that John she sounds in pain again...
Good luck at the vets...

I would say something is pinching somewhere pOst collision. An mri is the best bet as an X-ray won't show anything non structural.