Driven to the brink of breakdown by her son’s tragic accident, an anguished mother must learn the art of letting go before her guilt and grief destroy them both.

In this logline the personal connection is clear; mother - son. Therefor there is no need for "Driven to the brink of breakdown..." in the logline.

Better to start with the inciting incident as its impact on the MC needs no explanation.

Further letting go is a vague goal as it could manifest itself differently in each person, more so learning it as an art form. Better to specify an action that will be a clear cut acceptance of the son's death doesn't kill herself, stops drinking or doing drugs.

Lastly "...guilt and grief destroy them both." is a vague stake because we can't imagine a specific visual in our minds of what that means. We don't know if destroy refers to each of them as people or to their relationship as mother and son.
Do they become depressed? Do they both want to commit suicide? Will they argue and never speak again?

Hope this helps.