Cultural appropriation or appreciation?

I'm Irish white. I have 2 older brothers, one of which is 22 years older than I am. My oldest brother met my SIL when he was 18 so I grew up knowing her. She is from Puerto Rico. We spent lots of time together, and she treated me as her baby sister. She taught me about her culture, and even taught me to be fluent in Spanish (I loved her, she was one of my favorite people and still is!) I loved Puerto Rican culture and I regularly participate in those traditions because I've come to have a deep appreciation for that culture through my SIL. I was recently told that this was cultural appropriation because I am not a part of that culture. What do you think?