Sitting in my lap, Peggy reached toward my table, touched a beer can
and said, very precisely, /caen/. She was quite pleased with herself.

Relevance: Peggy’s evident pleasure I interpret as evidence that she
knows she has “caught on” to naming — that even though sounds may
be ever so similar (as /vaen/ and /faen/ and as /faen/ and /caen/, one
can make a one-to-small-number correspondence between words and
possible meanings. (“meanings” here being the names of things or
relations.)