The 19-year-old midfielder has scored one goal in six appearances this season after making his Addicks debut in the Capital One Cup.
Powell has admitted that he is impressed with Cousins's form since coming into the team.
"Even if things aren't going well he has got a terrific hunger and attitude," Powell told BBC Radio Kent.
"I think he will just grow in stature and confidence the more he is around myself and my squad. He is a skilful player, is calm on the ball, composed and elegant. It just shows what our academy is about.
"I know I have got major injuries to five key players - players that would always be in my 18 [matchday squad] if in form and fit - but Jordan has come in and looked at it and realised he has half a chance and has certainly taken it."
Charlton face Blackpool in the Championship on Saturday.