Correct Answer: little

Solution : The correct choice is the third option .

Little refers to the age or size of the girl, implying that a young girl is missing in the speaker's colony.

The meanings of the other options are as follows:

• Less is used to compare quantities or amounts.
• So can be used as an intensifier, but it cannot be used as an adjective here.
• Few is used to indicate a small quantity and cannot be used to describe a girl.

Therefore, the complete sentence is: "A little girl is missing from my colony."