When this invocation was first used, each person in a healing circle invoked a healer into (her/him)self. This was my invocation. The rest of the circle was asked to echo "Join us, Frigg" as I was saying "Join us. Frigg,". This was my first attempt at writing an invocation, and it DID work. I hope that it also works for anyone else who wishes to use it, because it now feels like time to share it.
Blessed Be, Russ

Frigg, Daughter of Jord, Join us.
Frigg, Daughter of Fiorgyn, Join us.
Frigg, Wife of Odin, Join us.
Frigg, Sister of Thorr, Join us.
Frigg, Mother of Balder, Join us.
Frigg, Mother of Hodr, Join us.
Frigg, Mother of Hermod, Join us.
Frigg, Mother of the gods, Join us.
Frigg, Wise in all fates, Join us.
Frigg, Who will tell no fortunes, Join us.
Frigg, First among the Asynjur, Join us.
Frigg, Queen of Asgard, Join us.
Frigg, Mistress of home and hearth, Join us.
Frigg, Mistress of Eire, Join us.
Frigg, Mistress of healing, Join us.
Frigg, Your servant _______ calls you! Come to me NOW!