Its a real hell for you... and I do so sympathise.

I take it that her tail is just lying still, not moving around? this often happens as a result of nerve damage.

Really in a case like this the Vet should advise you, and if they have not, then I have to think its too early for them to do so.

If urine has to be expressed, then you cant go on..

I do however agree with you, leave things till Friday before making a decision, then at least you can look back on this and say, I did all I could.

No tail amputions, nothing till then.. She may still be afraid to move, and if she has had urine expressed, has no real reason to move..

She is eating, drinking.. I agree with the other poster, who says, this is positive, now she can hold onto solids in the system for a long time, but urine, no.. so lets pray she drinks and drinks and has to use that tray..