You have to appeciate her and the things she does for you.She knows that she isn't perfect,but the thing is she's trying to be the best for you.Sure,she may make mistakes here and there maybe she get's upset at times,but know that she love you and that she is afraid to lose you.She wants to know that you will stay even when at time things may not always go right,but then again no relationship is perfect anyways,right?Let her know that you care and assure her that you are there to stay by here side through the highs and lows of relationship.
Love her regardless of her flaws,regardless of her pasts,regardless of what people may say about her or you two.Simply love her for who she is and dont try to change her into someone when she is not.Leave the past where it lays and move on future because that is what counts now.However,you can learn from her past so that you know why she is the way she is.Show her that she worth it to you,you know?Even through her imperfections you still love her and in your eyes she is perfect just the way she is.
