Hi Karen, glad you got her to the vet and are beginning some explorations. I was going to agree with Nicki, generally with a dog showing any pain it is a good idea not to walk them at all or only very little for toiletting etc.
I don't think any form of alternative medicine will deal with this kind of pain issue, whether caused by the leg or back -- these are as you have said, fairly serious issues that do often need surgical repair to give any quality of life. For a dog in a lot of pain it would be a better option to lose the leg entirely than try and struggle on with the pain and using lots of painkillers, if a repair surgery couldn't be done or afforded.
But we can easily worry too much about things that never have to happen -- it is much better to consider the possible options but try not to worry too much until you really know exactly what you are dealing with and what the options are. Most vets if they have a good relationship with an owner, will work out a payment schedule over time that can make even a costly procedure more affordable.
These kinds of challenges are so difficult but unfortunately they are not uncommon in this breed and probably is going to make owning a cavalier a greater commitment for people in future -- so many need patella surgery, many need costly diagnosis and care for CM/SM, almost all will eventually be on heart meds for MVD. It is deeply frustrating and places kind and loving owners, who adore their dogs, in difficult situations too many times. It's certainly why I never homed a rescue cavalier over the years without encouraging owners to do as you have done and take out insurance but then as rescues are older dogs most of the time, often there are these exclusions.
Fingers and paws crossed :xfngr:
this doesn't turn out to be a costly or long term problem.
Many people do not actually realise how widespread hip dysplasia is in this small breed, associating it with larger breeds. When I looked up the hip score averages for breeds, cavaliers are actually at far greater risk, with poorer average hip scores, than many giant breeds including Pyrenean Mountain Dogs! Some great breeders like Laura Lang in the US have long been outspoken (and snarled at for being so, by other breeders) about how hips ARE a cavalier issue & should be checked before breeding -- she hip scores all her breeding dogs. It can be very, very painful for the dog, and I know you will prioritise the right care approach for little Sadie and we will all be thinking of you and of her. :flwr: Let us know what the vet says as further tests are done, hoping it will be easy to manage with crate rest and painkillers.