If your dog refuses to go to the bathroom outside, it's only partially her fault. You have to develop and maintain a consistent schedule, because if you don't enforce it every day, she could revert back to her old ways. Stubborn dogs don't act the way they do because of a lack of rules, but rather because of a lack of consistency in enforcing the rules. Set up a routine, and she'll change her tune.
Take your dog outside to eliminate after every feeding. Wait about 30 minutes after your dog finishes, then take her outside. If she doesn't produce anything after a few minutes, take her back in, wait 10 or 15 minutes, and try again.
Continue taking your dog out on a regular schedule of about once every two hours. Once she gets in the habit of going to the bathroom outside, you won't have to maintain such a rigid schedule. For now, though, she needs to break her bad habits and get used to doing her business outdoors.
Visit the same spot as her last outdoor elimination. If she smells her scent there, she's more likely to do it again in the same place. Immediately after she eliminates, shower her with praise -- you can even give her a treat.
Wait until she eliminates outside before taking her for a walk. Don't think that if you walk her long enough, she'll go to the bathroom. Going for a walk is a reward for a dog, and she shouldn't be rewarded if she doesn't do what she's supposed to do when you go outside.
Practice confining your dog to discourage it from eliminating inside. Dogs don't want to eliminate where they rest, so your dog's crate should be just big enough for her to go in, turn around and lay down. Keep her in for a few hours at most, then take her outside immediately when you let her out. And like any time she eliminates outside, lavish her with praise immediately.