That is assuming she was born in winter :P if you don't know an exact date just pick a season close to the timeline you know the character originated.
@[Memphis] was born Helovia Tallsun 3, around October/November 2013, so counting from then until now, we're in Frostfall 4, he's only 2 seasons old or 6 IC months.
@[Parelia] So look at the chart to find September 2013, that was Helovia Birdsong 3. So she's been on Helovia for about 8-9 months. How old was she when she arrived?
Looking at her history you account for 1.7 years of her life, but don't say what season she was born in (spring usually for horses) or what age she was when she joined Helovia (your age currently says 4).
Assuming she was born in spring and was 4 years old when she joined Helovia she will be 5 in Helovia Birdsong 4 and would have been born around May 2011.
Helovia Hard Mode