Little Sister's First Period!!!!

Hi all! I'm 16 and my little sister is 10. We dont live together but we talk all the time! She told me yesterday that she got her first period and it was her second day of bleeding. She didnt have any questions for me but I really wish she did. I've had a period since i was 9 but i never had any questions, i kinda just learned things on my own. However, i wanna help my sister whenever she needs it since i didnt have a big sister to give me advice. What're some important (or not important lol) things i could tell her to help her through her first few months?