Suggest Treatment For Persistent Cough With White Foam

My grandaughter had strep throat which was helped by medication, however she has now been coughing lots of white foam out every day into a large cup she keeps by her bed. She is only 18 and has not been helped by her father. She appears exhausted and pale, and has not seen a doctor for these symptoms since she got antibiotics for her strep throat a couple of weeks ago. Although she is 18, she has not been helped in obtaining insurance, and her condition has not improved. How dangerous might this be if she does not see a doctor? I am her grandmother and very concerned that she is not being helped by her father. My e-mail address is YYYY@YYYY .