On the one hand a story is a story, putting more words in it doesn't make it more the story it just makes it the story with a bunch of extra verbiage growing over it like ivy up a wall or mould on cheese.
On the other, if you have this terrible feeling that the bit of the story you've told is too light or unfinished then maybe it is.
The problem is that, as the author, you have probably spent some time thinking about your story. If you haven't then problem solved, take a break, re-read the chapter fresh and think about what you're trying to achieve in this chapter (other than some arbitrary number of words).
If you have thought about it a new problem comes up. A story is a very particular type of communication. A communication intended to enthrall and entertain. In order to achieve this the story must tell audiences exactly what they need to know as they need to know it.
The nagging feeling that this chapter is "a bit light" is a symptom that you have been restricted from delivering necessary depth or interesting plot information because you are somehow restricted by what the audience currently knows or doesn't know. The liberty to make the chapter more complete may be found by reviewing what's already written and trying to find out where there's information missing. Essentially there's a possibility that you need a "pay off" but you never did the "plant".
However, you could just be over thinking it and the chapter may just be suitably eloquent and perfectly concise. These are the problems of balance you must overcome on your own.