Darling bursting at the seams almost? How elegant! (8)
I believe the answer is:
graceful
'how elegant' is the definition.
(graceful can mean elegant or poised)
'darling bursting at the seams almost?' is the wordplay.
'darling' becomes 'grace' (Grace Darling saved lives after an 1838 shipwreck).
'bursting at the seams' becomes 'full'.
'almost?' means to remove the last letter (most of the word but not all of it).
'full' with its final letter taken away is 'ful'.
'grace'+'ful'='GRACEFUL'
(Other definitions for graceful that I've seen before include "Elegant in movement or manner" , "Moving easily and elegantly" , "Elegant and moving easily" , "Fluid" , "Elegant, moving beautifully" .)