。
She made herself a delicious meal.
Literal
She [topic-は] her own self [for-のために] delicious meal [object-を] made.
~のために ('for the sake of, for the benefit of') marks the beneficiary of an action. 自分のために ('for oneself') is a common phrase that signals a small but pointed gesture of self-care: cooking specifically for oneself, as opposed to for family or guests. 料理を作る ('to make a meal') is the standard collocation; 料理 covers prepared food generally.