The identification with the subject (the wife of Antonio da Montefeltro, described in Baldassarre Castiglione's Book of the Courtier) is confirmed by a medal attributed to Adriano Fiorentino. However, the attribution to Raphael remains disputed, in a similar way than the Portrait of Elisabetta Gonzaga of the Uffizi. Emilia Pia was in fact a confident of Elisabetta Gonzaga, and perhaps her portrait was executed to emulate the former's.
Emilia Pia
Elisabetta Gonzaga