Firstly, I would like to make clear that your dog is well...a dog. They can smell a lot of smells. Your dog follows you inside because she is not distracted by unfamiliar stimuli, but outside it's a whole different story. You cannot expect her not to mind all her surroundings, it's just how dogs are. As a dog owner you should be aware of that.
You can try to teach her to come when you call her. Begin with walking her on a leash and teaching her to follow you when you call her. Say things like "-name-, come!"(or other short dog phrases) or whistle in a certain way and just tug her really gently. That's how I taught my dog to follow me. Keep in mind that communication is important.
Lastly, as Ceasar (hope you know the guy with the TV show about dogs, if not look it up you might learn some useful information) always says you have to be a good leader. Your dog has to see you as someone they want to follow. Your dog has to trust you, respect you and care for you. You can't achieve that without caring for her too. So let her do her dog things a little bit, wait for her and call her only if you think she stays too long. If you don't like doing that and if you really like keeping a "good pace" don't take your dog with you and enjoy a beautiful walk alone.