No worries - it's a different sizing system that's for sure. According to the information I could find, as my personal knowledge of sizing from Target (where I bought this) a size "2" is equivalent to an 18/20 in women's sizes. I hope this helps!
Such a good question - I'm 5'4", and when I hold it up to me it comes to about 2 inches above my knee. At 4'10" I don't think it will be above your knee, but it might fall right about that area. Sorry I couldn't help more!