To cry as a girl (5)

I believe the answer is:

toyah

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'a girl' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'to cry' is the wordplay.
'cry' becomes 'yah' (I can't explain this - if you can you should believe this answer much more).
'to'+'yah'='TOYAH'

'as' is the link.

Can you help me to learn more?

I've seen this clue in the Evening Standard.

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