Thank you for your thoughtful, reasoned and well written post. Refreshing really.
As you said, grief is normal and everyone deals with it differently. However if someone is unable to function due to extreme grief or more likely the resulting depression; they can’t work, are unable to enjoy anything in life, withdraw from family and friends, even stop taking care of their homes or themselves and it persists over an extended period, weeks, months years, then that is not normal grief and counseling or even in some cases, medication is probably warranted.
In the case of severe depression with severe suicidal ideation , I have sent a patient to a psychiatrist for medication, not for counseling as I kept that patient with me. Medication is the only reason I would involve a psychiatrist. Even doing that is “iffy” with a patient I described above and that is because a depressed suicidal person usually doesn't have enough emotional strength to kill themselves but if they take an antidepressant and get a little better, then they have the strength Io actually go through with the suicide. Working with suicidal people was a specialty of mine.
A story: A patient told me she was going to kill herself. I said, “Gee, I hope you don't do that because it would make me look bad - a patient of mine killing herself.” The lady said, “I never thought of that - I would not want you to look bad so I'm not doing it.” It's important for the therapist not to freak out if a patient brings up suicide. A calm response from the therapist is much better.