"The girl has little bread."
Translation:Het meisje heeft weinig brood.
Good question. In this sentence, "brood" is an uncountable noun. Because it is uncountable, it doesn't get the article "een", but the adjective "weinig" is conjugated as if it did. Because "brood" is a het-word and has an indefinite article (sort of), the adjective doesn't get an -e at the end.
The same holds for other uncountable het-words like "fruit" (fruit), "geld" (money) or "tijd" (time).
"Ik heb weinig fruit/geld/tijd" - "I have little fruit/money/time"