Hello, it is possible that your baby may have injured her cruciate ligament and that is why she is still having trouble being able to walk. Most of the time the ligament needs to be repaired surgically and that is the only way they will get use back out of their leg. The splint would not do much good in this instance except for possibly let the leg heal with the ligament contracted. If the ligament healed contracted then it would not have as much room to work so it would be unable to be used after the splint came off. I would ask your vet about the possibility of a torn cruciate ligament and see if they would be able to repair it surgically. That will take some time to heal but your baby will get full use of her leg back after recovery (about 6 weeks). I would ask for your vet to re x ray the leg and to also palpate th e knee to see if the knee is loose and confirm the ton cruciate ligament. I hope this will help you but let me know if you need anything else. Here are a some links with info on cruciate ligaments.