As any younger sibling knows, your older sibling is like a crash-test dummy. You get to watch him or her go through the trials of growing up, all while taking notes on what not to do when you reach that point in life a few years later. Lucky for 3-year-old Rain Tolentino, when her first period comes around, she will know for sure that it doesn't mean she's dying.According to Buzzfeed , when she caught a glimpse of her 16-year-old sister Meeiah in the bathroom during her period, Rain assumed the worst. In between sobs, she told Meeiah, "You're bleeding!" When she wasasked what she thought was going to happen to Meeiah, she responded, "You're dying!" Meeiah immediately reassured her little sister that what was happening to her was, in fact, a totally normal bodily function, and that she was certainly not "dying" — and Rain soon "went [back] to her normal, happy, self," Meeiah told Buzzfeed.Of course, like any good big sister, Meeiah caught the entire moment on video and tweeted it outlast week. As of the time of writing, the tweet has over 100,000 likes and nearly 85,000 retweets.Sure, as a 3-year-old, anything involving blood is pretty scary, and it almost goes without saying that we need to have more frank conversations about menstruation with young people. That said, if you ever have to give the puberty talk to a very young sibling, we recommend that yoube patient, keep it simple, and have your phone ready to go if kiddo's reaction is as priceless as Rain's.Check out the full video below.