The nasty argument left her unperturbed. (She was not bothered)
unperturbed
The boy was remarkably unperturbed by the terrible news.
He doesn't seem unperturbed by the comment Eric made.
Despite the chaos around her, she remained unperturbed and continued to focus on her work.
unfazed
That is the correct spelling of the word "unperturbed" (unaffected, calm).
Composed, undisturbed, unruffled, or placid. Those words mean unperturbed.
calmtranquilplacidundisturbedunstirredcollectedserene
Undisturbed, calm and collected
Calm, unruffled, serene
Not to disturb someone or something
びくともし