It’s clichéd but true that everyone grieves in different ways. Grief is almost always seen as a private matter that elicits widespread sympathy. But, people also grieve for losses that society is not always expecting or allowing. This is known as disenfranchised grief, as defined by the APA Dictionary of Psychology:
disenfranchised grief: grief that society (or some element of it) limits, does not expect, or may not allow a person to express. Examples include the grief of parents for stillborn babies, of teachers for the death of students, and of nurses for the death of patients. People who have lost an animal companion are often expected to keep their sorrow to themselves. Disenfranchised grief may isolate the bereaved individual from others and thus impede recovery. Also called hidden grief.
You can read more about disenfranchised grief in Dr. Kenneth J. Doka’s chapter of Handbook of Bereavement Research and Practice: Advances in Theory and Intervention titled “Disenfranchised Grief in Historical and Cultural Perspective” and in Coping With Infertility, Miscarriage, and Neonatal Loss: Finding Perspective and Creating Meaning, by Amy Wenzel.
VandenBos, G. R. (Ed.). (2015). APA dictionary of psychology (2nd ed.). Washington, DC: American Psychological Association.