Fable's a real beauty. I don't have any experience with this, but the wedge to lift the heel sounds good. I'd think it's critical to keep any tension off that tendon as she puts weight on that leg. Maybe there a way to combine the two ideas-keep the splint, add the wedge with it? That way she'd have the support of the splint, especially when she gets up. And with the heel lifted too, to minimize pull on the tendon. I think if she were my girl, I'd ask for both. Watch the other hind for signs of strain since it's doing double duty and lots of loving on her. I know she's getting plenty of TLC.
:grouphug::grouphug::grouphug: Please keep us updated.