absent-minded, distracted
Ella no es tan despistada como para decir eso.
She isn’t so clueless as to say that.
Ella es bastante despistada.
She's pretty absent-minded.
Ella es despistada y poco formal.
She is absent-minded and informal.
Me haré la despistada.
I'll pretend I don't know.
— Casi famosos (2000)