Both Uses of

competent
in
Cujo

Actual spot production was handled by a small independent studio in Boston, the New York market-analysis firm went on doing its thing competently, and three or four times a year either Vic or Roger flew to Cleveland to confer with Carroll Sharp and his kid — said kid now going decidedly gray around the temples.†
*

competently = in a capable or adequate manner

And she had let him take over and be competent, which she hardly ever was in emergencies; she usually just turned to mush.†

competent = sufficiently capable

Definitions:

(1) (competent)
capable (able to do something in a generally satisfactory manner) -- sometimes specifically to have legal capability
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

In the field of law, competent has the specialized meaning of being legally qualified to do something such as to be mentally fit to make reasonable decisions; or to have jurisdiction or authority to take an action.

In classic literature, a competency can refer to having an income or assets to support living expenses.