What happens if a starseed decided to leave?

A starseed I’m really close to just took her life.. it left me so confused because she always told me about her bigger plan or mission here on earth but she decided to leave… does that mean I have to carry her mission now? She’s my sister, by the way. She’s told me before I’m her twin soul… or I guess it’s up to me now what I’m gonna do next with my life? It’s not the “I have to” but actually I wanna make her dreams come true. Anyone knows any starseed who took their own life? What’s next?