How do you know when it's enough?

My 14yo dachshund has had IVDD recurrence three times now. Last episode was 2 months ago and she’s only partially recovered. She still wags her tail when I come home, still loves dinner, but she clearly hurts walking even short distances. Vet says we have ‘options’ but won’t make the call for me. How did you know your dog was telling you it was time?