Her writing style bears no resemblance to Shakespeare’s. Her poetry shows a much more conventional and religious writing style more closely associated with the time. Her verse is far more conventional and religious, while Shakespeare's pushes the boundaries of writing for the period.
Her life experiences and the frequent use of her name in the plays are also not evidence of her having written them. If, as many scholars have suggested, Bassano did become Shakespeare's mistress, it is likely she would have told the Bard many details of her life. She may have been a source of inspiration for him in his work.
The evidence is circumstantial at best. There is nothing to definitively suggest that Bassano was anything more than a friend or mistress who inspired Shakespeare and conferred experiences of foreign lands and literature which would later feature in his plays.