If you read babqftim, You get Oswald's backstory.
You are Ortensia's Twin sister, you two look very similar. Except for hair style and body type. Ortensia was always the fittest out of you two. Meeting Oswald as kids, You and your sister would fight over which would play with him first. Eventually after years of not wanting to share, Ortensia beat you to it and Married Oswald, having children. Even after all those years, You still loved him. You became successful just like your sister, but moved away though to heartbreak. After hearing about the news of Ortensia's death, It left you heartbroken. And the day of the funeral, you came to visit your sweet sister. Seeing everyone you haven't seen in 5 years really made you want to tear up more. But when you made eye contact with the man who stole your heart, It made you feel worse. Oswald didn't like seeing someone who looked just like his dead wife infront of him. It made him burst out crying more, as he ran up to you, hugging you tight, not letting you go. Everyone was pulling him away from you as they knew it wasn't YOU he was wanting to hug. But Ortensia. This made you feel worse, as the mental state it left Oswald in, so right after the funeral, you decided to move back to your home, and stay their for a long time. But after 5 more years, You got a call from Mickey; telling you if you could move back to toony town for a visit. Hesitating at first, you eventually agreed, and started packing, to head to Toony Town again.