And you? You're unhurt?"
"Of course I'm unhurt! Whose wife do you think I am? A few soldiers tried to bust their way in, but I busted them right back out—with my frying pan!
Sheila is Yang Fang Leiden's wife and a non-player character in Final Fantasy IV and Final Fantasy IV: The After Years. She is unlike her husband in the fact that she tends to use violence to solve most problems, such as beating Baron soldiers with a frying pan.
In all versions of Final Fantasy IV other than The Complete Collection, Sheila is simply referred to as Yang's wife (ヤンの奥さん, Yan no Okusan?), though the Final Fantasy Character Ultimania revealed it to be Ursula. However, in Final Fantasy IV: The After Years she is named Sheila and Ursula is the name of her (and Yang's) daughter.
Sheila is first seen during the Battle of Fabul. If spoken to after the siege, she tells the party she used a frying pan to beat Baron soldiers out of her room. Afterward, she says her goodbyes to Yang as he and Cecil's party leave for a ship heading to Baron (in the DS remake, she also gives the party the Counter Augment at this time).
Later on, Cecil and his friends seek her out after they find Yang resting in bed, guarded by the Sylphs. She tells Cecil to hit him with a frying pan. After the Sylphs tell the party Yang should rest (and offer Rydia the ability to summon them), Cecil returns to Fabul, and Yang's wife gives him the Knife, the most powerful Throw item for Edge.
While Yang is away at Damcyan celebrating its reconstruction, Sheila goes into labor. A pair of monks are sent to inform Yang, he along with Cecil and Rosa returns to Fabul. Sheila gives birth to a baby girl when they arrive, and Yang asks Cecil to be her godfather and to name her. Cecil agrees to both, and names the baby Ursula.
Sheila appears seventeen years later, with her daughter Ursula. During the Gathering tale, the player has to go to Fabul and talk to Sheila in which she gives the player a ladle and frying pan, used to wake up Yang and Ursula.
The name Sheila comes from a Celtic/Gaelic root that literally means "from the name Cecilia."