Take her to the vet and have them short clip her nails. I wouldn't try this yourself, because giong too short can hurt them. Not only will this cause less damage to your doors, but the feeling will bother the dog and it will stop (this works for digging as well). Get her something else to let you know she needs to go. They make doorbells for dogs. It doesn't take much time at all for you dog to catch on to this. Help them ring the doorbell each time before you take them out. Be careful however... they could use this against you anytime they want your attention

Good Luck!