Dump nosey model making a new name for herself (9)
I believe the answer is:
pseudonym
'a new name for herself' is the definition.
'dump nosey model' is the wordplay.
'model' indicates anagramming the letters.
'dump'+'nosey'='dumpnosey'
'dumpnosey' with letters rearranged gives 'PSEUDONYM'.
'making' is the link.
(Other definitions for pseudonym that I've seen before include "Also known as" , "in the style of George Eliot?" , "Boz was for Dickens" , "Lewis Carroll, for one" , "Pen-name" .)