I'm so sorry that you're going through this. A number of my friends parents went through a divorce at some point during my childhood and teenaged years. It's painful and difficult. One thing to remember is that you're not going through this alone. One of my friends told me how it sucked because she felt like she didn't have a family any more. Later her dad remarried to another woman and she ended up with step sisters and seemed to enjoy it more. So eventually you'll be able to adjust to the new normal.
Like has been suggested, talk to your sister because she's going through this. Plus, I'd recommend looking for resources online (e.g. mediation and family counselling) because it might be worth it to access those resources with your family if your family is able to afford it. Many Canadian cities have these services offered for free or at low cost. It sucks to have to be the one to initiate this since you're just a kid, but I think it's a really good idea to navigate these tough transitions with a therapist