Here's the
index to SAR related subjects discussed in FinCEN publications. I'm not certain this meets the standard definition of a 419 scam, but "advance fees" is the first topic listed so you will be able to judge.
You did not provide an amount or any indication whether your customer lost money (relevant if this is determined to be a 419 filing), so there is no way to be certain whether a SAR is necessary.
As soon as your customer accepts the fact she isn't coming, he can file his own report
here.