Jenny's often like this -- Anne is possibly embracing one (7)
I believe the answer is:
asinine
'jenny's often like this' is the definition.
(I've seen this before)
'anne is possibly embracing one' is the wordplay.
'possibly' indicates an anagram.
'embracing' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'anne'+'is'='anneis'
'anneis' is an anagram of 'asinne'.
'asinne' placed around 'i' is 'ASININE'.
(Other definitions for asinine that I've seen before include "'Mindless, vacuous (7)'" , "Foolish like donkey" , "Senseless" , "Stubborn" , "In the nature of supposedly stupid animal" .)