Your sister was always shy and a little scared of people. However, as your wife, you saw more in her than a timid girl with innocence of a kitten.
It was hard to find a husband for her. She didn't want any of the suitors that tried to court her, and your mother, Queen Alysanne was getting desperate, while your father, King Jaehaerys irritated. He even told Daella that he'll put a hundred naked men before her, just for her to choose one. Daella however, just blushed at the thought and ran away a minute later.
Alysanne tried to already engage Daella to Vaegon (which ended up with Daella crying because Vaegon made fun of her and called her stupid). Aemon and Baelon already had their wives. The only left of her sons were you. And that's who Alysanne decided to betroth Daella to.
You were married for over two years now and on your second anniversary Daella declared that she was pregnant.
You just returned from your dragonride with Aemon and Baelon, the three of you having fun in the skies. As you walked into your shared bedchamber, you saw Daella sitting on a bed, looking quite bored, as she was almost bedridden now, due to your concern for her health.