Very happy, Penny left relieved (7)
I believe the answer is:
pleased
'very happy' is the definition.
'pleased' can be an answer for 'happy' (similar in meaning). I'm not certain of the 'very' bit.
'penny left relieved' is the wordplay.
'penny' becomes 'p'.
'left' becomes 'l' (common abbreviation).
'relieved' becomes 'eased' (easing is a kind of relieving).
'p'+'l'+'eased'='PLEASED'
Can you help me to learn more?
(Other definitions for pleased that I've seen before include "Euphoric" , "Glad" , "Grateful, delighted" , "Gratified" , "like Punch?" .)