Mother has short skirt, it's the very least (7)
I believe the answer is:
minimum
'the very least' is the definition.
'minimum' can be an answer for 'least' (I've seen this in another clue). I'm not certain of the 'the very' bit.
'mother has short skirt' is the wordplay.
'mother' becomes 'mum' (informal term for mother).
'has' is a charade indicator (letters next to each other).
'short skirt' becomes 'mini' (mini skirt).
'mum' put after 'mini' is 'MINIMUM'.
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for minimum that I've seen before include "Lowest value" , "Lower limit" , "Smallest possible quantity" , "Bottom" , "Least possible quantity" .)