@Charlie, I think you need to ask the vet why Hattie is tripping up on her front legs and the wobble on back legs? Maybe as she is getting older she is getting weaker as we all do, perhaps some hydrotherapy would help? As you may remember Rourke has arthritis in both shoulders and left hind hock (he has bony lumps there) and also tendonitis and has a very pronounced lameness on his front, he cannot take Metacam as it causes stomach bleeding. You may find that CBD oil will help with any pain and I also give Rourke Yumove EXTRA which you can only get from the vet, also Fish for Dogs, salmon oil. I think the CBD oil helps with pain as Rourke appears to be happy when out, despite the distinct lameness. Hope this helps. Try not to worry, worry isn't going to help either of you. As it is supposed to say in the bible 'worry never made a short man 2" taller'.
So you could try hydrotherapy, CBD oil (that was recommended to me by a vet), Yumove Extra and Salmon oil. But I am not sure the tripping, wobble etc is arthritis, could just be old age or something else which is not causing pain.