Board Thread:Character Discussion/@comment-26062156-20150131174600/@comment-24674051-20150204145253

Honestly, I don't remember if they said anything in the movie about how old the girls are, and they definitely did not mention specific ages in OUaT.

However, let's consider that from the time that the King and Queen died in the Shipwreck to the time of Anna's wedding at the beginning of Tale of 2 Sisters is 5 years. Elsa is Queen. Couple that with the Movie, where Elsa is crowned queen 3 years after the shipwreck, and we see that Elsa has been Queen 2 years.

Obviously,  Elsa was not immediately crowned Queen after her parents death, which would imply that she needed to reach some age of ascent. So I think it would be safe to assume that Elsa was crowned on her birthday, which just leaves the question of WHICH birthday. That age varied anywhere from early teens (some of the early British Monarchs were as young as 15 when they took the crown), to early twenties. Elsa's demeanor in the Movie suggests, imo, that she was probably 18 when she ascended the throne.

I see about 2 years difference between Anna and Elsa, making Anna around 16 at the coronation, and therefore 18 at the time of OUAT events (based on the given timeline).