She dyed her hair darker. It's naturally brown, she was blonde for a while and has now black hair. That's it. The make up, etc is always different anyways and she might have lost some weight while touring. I think Mai C's appearance changes are way more drastic - her hair is a different colour, lenght and style every few weeks. Or Hayley's - she went to very dark hair form originally being a blonde. When Lisa K was still with CW her hair colour changed just as often as Mai C's and she experimented with cuts and bangs, too. I really don't see the trouble about changing one's appearance - especially considering Éabha's changes are absolutely minor compared to some of the other girls. It's not like she changed anything about... I don't know her face or her body. Hair is always different and many women dye it.
Eabhas hair is in NO way black! its just dark brown. She said when she dyed it that the color she dyed it is her natural color & she wanted it that way. As for her weight, she has always weightlifted apparently so she wants to continue to maintain her current health. No big deal about that.