Indicas are definatly you cola dominant strains as they then to be shorter than their Sativa counterpart. However this does not mean this happens 100% of the time, it all depends on genetics really. The only true way of knowing is trial and error by yourself and finding strains that fit your needs.
As far as your girls go it looks to me like a bit of nitrogen deficiency, easy fix just add some nutes with a higher N content than what you are currently using. For example if you are using strictly blooming nutrients now mix in a bit of the nutrients you used during veg(assuming you vegged anyway)along with the blooming nutes with your next watering. Also be sure to keep a close eye on the PH of your water as coco tends to hold salt build up left behind from nutrient formulas. Hope this helps