Best Friend

My best friend is from Poland. Her name is Susanna and she's very beautiful. She has long blonde hair and green eyes, but in the sunlight they look blue. We met during school when the teacher has sat us next to each other, so we quickly became friends. We love going to coffee shops to study together, but we always end up talking. She orders a donut filled with jam and I usually just order coffee. We have went to vacation together, so we became very close. We'll study in the same university, so I am pretty sure we will be friends for a long, long time. Susanna is like a sister to me. Who is your best friend?