Possible Clues:

• Make it public that the girl gets a little light
• Broadcast (information)
• Let it be known that this sounds less than a pound
• Declare about twenty-eight grams, say
• Declare a small animal, say?
• If she puts on even so little weight she'll tell you all about it
• If the girl puts on a little weight she will tell everyone about it (8)
• Make known girl wait, say
• Proclaim or declare to be a lightweight
• Applied acid test to art