I thought that in a sentence like this, יותר טובה could mean "the best". Is that wrong?
I remember a sentence from a couple of exercises ago where it meant "too good", as in "The team is too good". This is a confusing sentence!
This sentence seems incomplete - better than who? Or in Hebrew does it mean she is a really good boss?
Well, I do not think that Hebrew really has comparative adjectives that mean a considerable or excessive degree of quality like Latin brevior "rather short" or audacior "too bold", but if it is a null comparative, at least a thing compared has to be thought (like "People who live in colder climates") or must have been mentioned before.