Crossword Genius

Unworthy daughter is gesturing with finger, holding dad up (13)

Ross

I believe the answer is:

disappointing

I'm a little stuck... Click here to teach me more about this clue!

'unworthy' is the definition.
Both the definition and answer are adjectives. Perhaps they are linked in a way I don't understand?

'daughter is gesturing with finger holding dad up' is the wordplay.
I cannot quite see how this works, but
'daughter' could be 'd' (genealogical abbreviation) and 'd' is found within the answer.
'is' is present in the answer.
The remaining letters 'appointing' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

Can you help me to learn more?

(Other definitions for disappointing that I've seen before include "Failing to satisfy" , "Not as good as one had hoped" , "Poor" .)

I've seen this clue in The Times.
Want a hint initially instead of a full solution? Install my app