Thanks Fiscal. I know dd always runs a very high temp when she's going through the virus crisis, then it breaks and she's better. The amount of times we've rushed to the OOGP and been sent home has taught us to wait a little.
Sure enough, no sleep for dh and I last night, but the fever has broken and she's currently sitting in the rocking chair singing and doing her new sticker book. I am so relieved. Even though I know it's her 'pattern' for this sort of virus, it still scares the proverbial out of me every single time!
New worry this morning. Last night Pip yelled out all of a sudden, then held his back leg up and looked really panicked. (This is the leg he had the knee injury on just before Christmas.) His toes looked scrunched up and leg tight, so I thought it must have been cramp. Massaged it and he went back to sleep. Then he went to get up from sleeping at my feet when we went to bed, screamed and couldn't get up. Can't work out why. Checked both legs and his back and he doesn't seem to be sore anywhere, but he did it twice. Tried to get up when I got off the sofa and couldn't so stayed there, then tried again when dh got up and managed it, but was moving very stiffly on his back end. Was all set to call the vet this morning, but he seems fine again. 
I have noticed him being awkward getting up a few times over the past week or so and checked him over, but couldn't find anything and he seemed fine once up.
I think the two possibilities are, that it is the leg he injured or it's his back. Being a Lurcher, he has a long back and something about the stiffness of his gait last night made me think it looked more back than legs. Think I will have to book him a vet appointment early next week and get her to take a look at him. Problem being, it seems to be intermittent and even straight afterwards he doesn't have a problem being manipulated or have any areas of heat or painful points, which means she mightn't be able to get to the root of the problem either. 