My prayers are with you and your friend. This Sunday would have been my mom's 83 birthday and her anniversary. I miss her everyday and life has not been the same since. All I can say is this. Please just know how much you meant to her and that you will carry a piece of her spirit everyday for the rest of your life.
For myself, I get depressed a lot because I miss mom and want her back but I know she is in a better place. We all have a timer in life. I know your friend is in a better place but at the same time I do wish you some peace and please pm or if you need to talk call me anytime. May any spirit/GOd you believe in be with you and your friend!