A setback tends to hit hope in a specific way: it does not just delay a goal, it can quietly convince a person that the goal, or their ability to reach it, was never realistic in the first place. Rebuilding hope usually starts by separating those two things back out again, carefully, one at a time.
The first step is often the smallest one available: not the original ambitious goal, but some near, achievable action that proves capability is still intact. A small, completed task tends to do more for rebuilding hope than any amount of reassurance from someone else could manage on its own.
From there, hope tends to return in layers: a completed small step restores some belief in one's own agency, which makes the next step easier to attempt, which gradually restores enough confidence to look at the original goal again, this time with a revised and more realistic plan firmly attached to it.