Goat for Mary Poppins? (5)

I believe the answer is:

nanny

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'goat' is the definition.
(nanny is a kind of goat)

I cannot understand how the rest of the clue works.

(Other definitions for nanny that I've seen before include "butter" , "eg Mary Poppins" , "cares for child?" , "Issue tender" , "Undue government interference with personal choice?" .)

I've seen this clue in The Sun.

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