What Causes Shortness Of Breath?

Good day! My daughter s name is Carmela, 13 years old, 4 11 tall and weighs 48kgs. Last July 4, she had experienced shortness of breath while in school. she was brought to the hospital and admitted for a day to undergo 2D echo and doppler. The doctor said she has rheumatic fever and has a trivial Mitral Valve Prolapse. She has varicose-like veins on the back of her legs and on her shoulders, colored red. As per results of doppler results. 2D echo conclusion is: Echodense Anterior Mitral Valve leaflet with trivial regurgitation probably rheumatic in etiology while the Doppler Impression is: Deep venous insufficiency common femoral vein to posterior tibial vein bilateral; Superficial venous insufficiency bilateral; no evidence of venous thrombosis bilateral. She was given Phenoxymethylpenicillin (sumapen) 500mg, 1cap TID for 10days; while she was advised to wear compression stockings. But why is my daughter has a daily attacks of shortness of breath for about 2 weeks then after that, she had experienced pain and numbmess in her knee joints and right shoulder then just this week she experience backpains. Your answers regarding my querries will be very much appreciated. Thank you very much. Llane