Njoj se večeras ne kuha, a meni se ne da opet izlaziti, pa ćemo jesti ono što već imamo.

Because Croatian often uses the dative for the person who is experiencing a feeling, state, or impulse.

So:

• njoj se ne kuha = literally something like to her, cooking is not happening / she doesn’t feel like cooking
• meni se ne da = literally to me, it is not given → idiomatically I don’t feel like it / I can’t be bothered

This is very common in Croatian with impersonal expressions. English usually uses a normal subject like she or I, but Croatian often frames it as something happening to someone.

Here se is part of an impersonal/reflexive construction.

It does not mean herself or myself in the usual sense. Instead, it helps create expressions where Croatian avoids naming a clear subject.

For example:

• kuha mi se = I feel like cooking
• ne kuha mi se = I don’t feel like cooking
• da mi se = I feel like it
• ne da mi se = I don’t feel like it / I can’t be bothered

So in this sentence, se is a key part of the idiom.