。
There's no girl in my class cuter than Linda.
Literal
I [of-の] class [in-で] Linda [than-より] cute girl [topic-は] not-exist.
The negative-comparison pattern: 'than Linda, no girl [in my class] is cute' = 'no girl is cuter than Linda.' で marks the location/domain of existence. リンダより modifies かわいい. The noun-phrase リンダよりかわいい女の子 is a relative clause modifying 女の子. A classic comparative superlative construction.