My condolences go out to you and and your family, I'm sorry to hear this man. My grandma died approx a year ago now, and it's still quite sad now that she isn't there for my mum to speak to when she's sad...
Personally I don't know what I do believe but I know that if you believe in that and it makes you feel good to think of it that way then think of it that way. Its a nice way to see it all, that she wanted to see your mum and you before she went away but sorry for your loss and all, hope your alright