That model is really outdated, and was never meant to be the linear model it is so often presented as. I imagine you were speaking lightly, but it's important to call this out.
My wife is a grief counselor, and that is the clearest thing I've learned from her, and it's the single most important thing to share when people are dealing with grief. The prolonged use of this model in society and popular culture leads people to believe that we're supposed to progress through grief, and at some point "get over it". But grief is cyclical, and it's different for everyone.
Environmental grief is real, and it's a pretty crazy time to be a parent. How do you help your kid understand that the world you brought them into is quickly collapsing?