Shirley is not a person anymore, but in fact the spirit of the old White-Silver Dragoon. It is noted in writings that she was in fact the glue of the original seven dragoons. It could be said she was the kind mother who loved all and hated war. It is for this reason that Belzac, another dragoon, fell deeply in love with her. Whether her feelings were mutual is left unknown. Her standings with Rose were better than most, as the two women clearly respected each other in the time of war and in the time of her afterlife.
Unfortunately, Shirley died at the end of the Dragon Campaign. A huge stone roof had collapsed and bits of debris that came off knocked Shirley unconscious, but before the whole roof fell on top of her Belzac caught the roof and held it above Shirley preventing it from crushing her. However while he was holding it up, a Virage had spotted them and impaled its hand through Belzac. Belzac was slowly dying, but continued to hold the roof above Shirley in an attempt to save her. At this point, shortly after Belzac's impalement, Shirley woke up in a panic to see him dying. She quickly noticed the Virage and the situation at hand. It was not in Shirley's nature to leave an ally, especially one she may have loved, so she stepped up and told Belzac that his death would not be in vain. She quickly readied her arrow and put up a protective barrier, while the Virage prepared to fire its eye laser.
In her final moments Shirley shot her arrow and killed the Virage, but in this process the Virage exploded, killing Shirley and Belzac. However, Shirley feared the worst for her fellow Dragoons and, as a ghost, used some of her power to fix the souls of the other Dragoons to keep them bound in Vellweb to prevent them from going to the Death City of Mayfil. Shirley would go to her Shrine in Serdio, where she would preside, with Drake the Bandit guarding her, hoping that the new Dragoons would one day come and save her fellow friends.
During the battle with Shirley, she asks deep personal questions to Dart, Rose and Lavitz, peering into their hearts and transforming into their loved ones. When talking to Dart she will transform into Shana, if attacked while in this form, she will use the basic attack, it should be noted that the voice during this attack is not Shana's but a much younger sounding voice. While talking to Lavitz she will transform into Albert, if attacked during this form she uses the basic attack, but will not complete the addition, or she will use Albert's "Spinning Cane" Addition. As with the Shana form, the voice is not Albert's but that of a more warped being. If Shirley is attacked while in her normal form she will use a variety of attacks; the attacks she uses are listed below.
Random Light: Shirley uses a random light magic at max power.
Light Syphon: Shirley send out waves of light, at a party member that swirls around and absorb his/her HP, the HP is then transfered to Shirley healing her.
Healing: Shirley heals herself to full HP with a healing spell when her HP drops to 0.
At one point and time, Shirley was an available boss in her original Dragoon form, like Damia, Belzac, Kanzas, Syuveil in Vellweb, Zieg on the Moon That Never Sets, and Rose as part of the Dragoon tutorial in Hoax. However, her fight was ruled out, as the White-Silver Dragoon has a weak basic attack (Dragoon Addition) as well as possessing unlimited MP she could constantly heal to max HP with her spells, this would have made her an unbeatable boss, thus the creators excluded her Dragoon battle, but left the data on the disc.