The official Yiddish spelling of
Pearl seems to be
Perle. Perl would be sort of a halfway form between the two.
The custom in Ashkenazic Jewish families is for children to be given an "English" name which starts with the same letter as their Hebrew name used in the synagogue. If this woman was born in the USA, she may very well have been
Paula or
Pauline when she was interacting with the "American Gentile" world but Perl or
Perle within her own family.