A couple is two, a few is three, a handful is four or five, and several is six or more ... up to about ten when "many" takes over.
This sounds about right.
Oddly, I wanted to start a similar thread as my wife disagrees with me on what a "few" means.
In my context, "a few" is the answer I got for "Can I have some cookies" which meant 2-4 cookies, rather than as many as I can cram down my cookie hole.
that shaped my definition...