Have replied to a friends email using the return address but she is not getting my reply in Russia, why not?

I have recieved letters from her and I have sent letters to her but only 3 out of 20 have gotten back to her in Russia. I always send them "reply" so she should get them. What is happening, her email is polinkami@gmail.com can you notify her that David is trying or tell her what she is doing wrong or what I am doing wrong? is the gmail carrier the problem? I don't wnat her to think I don't answer her or don't care. She usually uses an internet cafe in Kiev, UK and they are charging her money to recieve and send any letters she gets , is this common practice there and how cn she avoid these charges? can you instruct her by email on a cheaper easier and more safe way? Please let me know why my mail is not getting to her. Write me back wioth any suggestions you might have for us. Thank you Dlfrankforter@yahoo.com