Hi Rose, you're not done. Plenty left to do. sometimes we give ourselves windows to leave, though, after we've learned a particular lesson. But we also have the option of continuing, since we're already here. it's sort of like an upsell. you already went through babyhood, why repeat that? Just keep on going and draw new lessons to you.
Also, you will recognize your loved ones on the other side by their energy signature. no mistaking it. Don't worry about that.
Rachelle, you can communicate directly with her higher self. do a meditation and go into a garden and ask her higher self to come to you. Talk to HS about your grandma and what might be holding her back from leaving. What is she waiting for? it might be a legitimate reason. Help her finish her life. Help her tie up loose ends.
You can also talk to your grandmother about letting go. She might get it on an unconscious level.