This is the 620th most frequent Swedish word.
hanna
"Hanna" is a Swedish female given name.
Here, 'Hanna' is used as a proper noun, a name.
Hanna är en vänlig person.
Hanna is a friendly person.
In this context, 'hanna' is used as a misspelling or uncommon verb; it might derive from an informal or dialectical variation.
Man kan hanna sig när det är stressigt.
One can calm oneself down when it is stressful.
Here, 'hanna' is incorrectly used; however, native equivalent verbs like 'hamna' could fit the context.