turning purplish can have a few reasons.. it can be either the genetics of the strain, or possibly a P deficiency..
looking at the first pictures the plant seems pretty light-colored, but that might just be the lighting, because the later pictures look a bit greener.. i'm not sure how much and how you feed her and if that could play a role..
anyways i wouldn't worry about it, and just keep an eye on it.
all in all she's looking very nice
happy growing!