"There is enough, you know."
It's a simple negative. 少ない looks like one in hiragana, but it is not a negative, simply an adjective that means "few" or "insufficient". It may sound weird to an English speaker because we do not have a word to mean "not enough" that's not a negative (explicitly or with a prefix).
I too am confused as to why we're using さくなくない, ie "not too little", instead of say じゅうぶん(十分) , which is the first hit in my dictionary for the English word "enough".
perhaps this English prompt could be better phrased as, "this isn't insufficient", although I'll admit that is an unusual phrase.
at any rate I'm flagging the question because there was no hiragana in the hovertext, only kanji... and i can't tell if it was even helpful kanji. both kanji and hiragana should be available as answers, i think, but if only hiragana is available, then having only kanji as a hint isn't helpful; i haven't figured out how to search by radicals yet!
Really awkward English sentence... Also it's a slightly different context to say 少なくない, i feel. It's like saying "there isn't few". It may carry the correct meaning if this sentence is used to respond to the right statement (食べ物が少ないね, or something) but a more direct translation might be 十分ですよ