I think getting a letters from your abroad program would be fine. D20’s college admission counselor suggested one recommendation from a STEM class and one from another core class (English, Foreign Language, Social Studies) and both should be from teachers you had as a junior or will have as a senior. My D had one from her 11th grade history teacher who taught her 12th grade sociology elective and one from her 10th grade math teacher who taught her again in 12th.