Starts skiing with her Dad, a mountaineer (6)
I believe the answer is:
sherpa
'a mountaineer' is the definition.
(I've seen this before)
'starts skiing with her dad' is the wordplay.
'starts' says to take the initial letters.
'with' is a charade indicator (letters next to each other).
'dad' becomes 'pa' (synonyms).
The first letter of 'skiing' is 's'.
's'+'her'+'pa'='SHERPA'
(Other definitions for sherpa that I've seen before include "High-up employee" , "Phrase for Himalayan mountain climber" , "Himalayan dweller" , "Nepalese mountaineer" , "Himalayan mountain guide" .)