The semicolon is not technically wrong. Some of the other teachers here would disagree me for changing it to a period. However, many editors discourage the use of semicolons except when they are truly necessary. The reason is that they are old-fashioned and seem ornate or snooty to contemporary readers.
Your English writing is excellent. I'm so sorry about the loss of your sister. It sounds like you've chosen a good path.
Student or Learner