I’ve very sorry. My grandma died almost 2 year ago now. My mom and aunt will never be over it.
My deepest sympathies to your mom and aunt- I don’t think it necessarily is something a person gets over... I think it’s more something we learn to live with. I know how deeply it affected our family when my dad passed away- but there was acceptance, and later, an inner healing. I suspect time will do the same here, right now there’s simply a numb feeling...shock, I suppose.
Above all else is the knowledge that it truly is not goodbye- to your grandmother, nor my mom- it is simply, “Will see you later!” Because we will-