how do we upgrade her relationship after the third stage i only found the hand wich make only +1 and a kiss +2 and i found every locotions she go but i never get anything who change
The best way to increase the relationship would be by unlocking conversation topics, this is achieved by asking her about the location where you find her (gym, library, etc.) with the question button.
When they are unlocked you will be able to see more dialogue options in the "Talk" section