An author need not be mawkish. There are plenty of routes to the heat strings. How he gets there is simply a matter of imagination and style.

Actually, I'd never heard of this word before, so I decided to trace its etymology.  Here's what I found: 

Mawkish comes from the Old Norse work 'mathkr'.  That word later evolved into 'mawk' (of Germanic origin) and , meaning 'maggot'.  It came into use in the mid-16th century meaning "inclined to sickness or nauseated".  It then evolved to mean "something so sentimental that it makes you sick".