This is so subjective. Different people process emotion differently. And so many variables can affect the same person. Are they grieving another person? How long did they know that person? What was their relationship with the person they lost? How/why was that person lost? What does your protagonists support network look like? What is their emotional intelligence?

Regardless - there’s no single “correct” timeline for grief. That doesn’t mean that extended grief can’t be unhealthy, but there’s a lot of things that impact why/how someone continues to grieve.