Nuns left fringe group from America (6,6)

I believe the answer is:

sister sledge

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'group from america' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'nuns left fringe' is the wordplay.
'nuns' becomes 'sisters' (nuns often use the title 'sister').
'left' becomes 'l' (common abbreviation).
'fringe' becomes 'edge' (synonyms).
'sisters'+'l'+'edge'='SISTER SLEDGE'

Can you help me to learn more?

(Another definition for sister sledge that I've seen is " 1 across all-girl group".)

I've seen this clue in The Independent.

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