I think my sister might be lesbian. Not sure how to approach it

Background: I am 2 years older than my sister. We were raised in the LDS Church and my sister continues to attend with my mom. So I have a younger sister about 19 years old. In the more recent years I have occasionally suspected her of being gay, mostly because she doesn't date, and her best friend came out as gay in high school and now they don't really hang out much. Anyway I was going on Netflix to watch a show a few weeks ago and accidentally clicked on my sister's profile instead of mine. I began to browse through and noticed a large amount of her suggestions being mainly romance and dramas with thumbnails depicting lesbian couples and such. About a week later I noticed she deleted her account.I honestly don't really care if she is lesbian an am fully accepting of it, but I just don't really know how or even if I should approach her about it and let her know that it's OK.Halp plz