It's not correct. For balancing, we need to put the coefficients in the molecule, not in the athom. Because if you do this, you're creating another molecule, instead of a balacing, for which the reaction may not happen - but anyway, it would be another reaction.
The correct balacing is:
2NaOH + 1H2S → 1Na2S + 2H2O
Explanation:
Look: Na2OH does not even exist. OH has only one free link, so he can't - in normal conditions - make another one with any athom. That's why we should write 2NaOH instead of Na2OH. The first means "2 mols of NaOH".
