Giselle recently lost her longtime partner, Gabrielle, to ovarian cancer. Giselle has been having a difficult time expressing her feelings of grief because she never told her family of her relationship with Gabrielle. Giselle's inability to openly grieve the loss of her partner is best described as

Incomplete grief

Explanation:

Incomplete grief refers to that phase of grief during which mourners get difficulty to move and is an emotion that remains over a period of time. To heal from this grief is become difficult sometimes.

In the above context, Giselle who has lost her partner Gabrielle, facing a very emotional time of grief as she doesn't have anyone to whom she can share her feeling.