yup incest cus why not
elsanna is hella canon yo

Anyways, after the whole "freezing over Arendelle" incident, Anna and Elsa realized the hidden feelings they had been harboring for each other and for a few months awkwardly courted each other without much thought. Kristoff was very much aware of this, and despite loving Anna he knew it would be selfish to lead her away from the pony she truely loved. So he set up a blind date for the two. They were surprised but were alarmingly happy once they told each other the truth.

The two married after a year of dating. The kingdom was not bothered by this, considering intermarrying in families was common. Elsa, with her alicorn magic, had a filly with Anna named Eira. (meaning "snow; help, and mercy" in Norse/Scandinavian)

Eira is a spitfire of a filly, taking a lot after Anna in the adorkable-ness department. She's fast and quick, adoring both her mothers and her playmate Olaf the Snowcolt. Eira has control of flurries, but not ice or large quantities of snow. She's the fastest when running across the snow of flying in the cool air, and has a good resistance to cold temperatures.

(Elsa used to be an pegasus before she transcended to alicornhood, during the song "Let It Go". This is why Eira's a pegasus.)