You need to ensure she has had enough exercise to start, she has learnt she gets your attention my running away. Ted occasionally tries this, he wants you to Chase him, he's just over a year old and I think it's a puppy thing, it's his way of playing, but not acceptable by our standards, by dog standards yes. When he tries this I ignore him, but point at the grass or something, pretend I'm picking something up and say "what's this", he normally falls for it and comes over, then I tell him to sit. Or I pick a stick or a toy up and say the same, wave stick or squeak toy, he normally comes running over 
just don't go chasing her, because that's wht she wants. I also have the same problem getting his to go out to toilet, I walk out the back door to the steps up the garden and say "go wee" and he starts to go up, if he stops they I touch his tail and tell him to go on. He goes up then, when I'm opening the door, in or out. I tell him to wait before I go, I hold my hand in front of him and say "wait", she'll get it eventually, she's testing you grounds
just don't go chasing her, because that's wht she wants. I also have the same problem getting his to go out to toilet, I walk out the back door to the steps up the garden and say "go wee" and he starts to go up, if he stops they I touch his tail and tell him to go on. He goes up then, when I'm opening the door, in or out. I tell him to wait before I go, I hold my hand in front of him and say "wait", she'll get it eventually, she's testing you grounds
