If her repertoire included Aurora, wouldn't that qualify her as a ballerina? (Honest question).
It is an interesting question you pose.
There can be quite a difference between dancers who perform ballerina roles and actual ballerinas for Baldina with her St. Petersburg training she would probably have stood out as having
a more refined style compared with her colleagues at the Bolshoi in those years she spent there which along with her highly talented husband's status ensured her getting leading roles.
It does depend who is measuring the status and the criteria being observed. If we talk about the ecole classique delineation of Danseuse Noble as equating with ballerina, many so called ballerinas of the past would perhaps, be excluded.
Today the title is generally obsolete except in the press. It was perhaps the power of the ballerina, especially the Prima Ballerina Assoluta, that brought about the title of Principal Dancer as an inclusive term for dancers who regularly perform leading roles which I think reflected an inclusivity of status within a company rather than the exclusivity of status of a ballerina or Prima Ballerina.
For those seriously interest in Academic Classical Ballet, who feel they know the criteria for a dancer being called a ballerina rather than a Principal Dancer also as matter of course perpetuate the term, but not everybody would set the same criteria for such a nomenclature.
I do not believe Alexandra Baldina was ever given the title of ballerina and every photograph I have seen of her she looks a demi-classical or even a demi-caractere dancer.
Miss Baldina appeared on Broadway in shows choreographed by her husband Theodore Kosloff and his brother Alexis.