Is ' hun blander alt' possible?
Sure, that works, too. "Det hele" is better translated as "it all", i.e. a very certain amount of things.
She mixes it all?
she blends it all?
is "she blends" OK?
Yes.
But if you're blending something in a blender, use "at blende" (pronounced like in English with an added [ə].
How can one in Danish hear the difference between æ and a?