Here, let me jump all over the place........I like the speckled cow's color the best. That is really pretty. I agree with Ricebeltrancher on the #3 being more feminine. But I can see she has a layer of fat, as there are no bones showing over her hips. Her tail head is still pronounced and the muscling has not developed in this areas. It appears to go flat over her loins, but then goes peaked over her rib cage. She doesn't appear to be as wide in the hips as #2. She could use a bit more muscling in the lower buttock area, as # 2. The #2 cow's muscling is not all fat. I have seen very heavy cattle that had light muscling and it did not extend the muscling if they didn't have it in the first place. It may add more fat to the muscle just as it does any animal. #3 has a bit longer hip and a bit more muscle ties well down into the hock area.
#3 is shallower through the flank and less spring of the ribs. Her leg is straighter.
I do like her head an neck better, but the other cow is caring a lot more weight.
What I have said does not make #2 a bad cow. It is just my opinion. If she was in my herd, I would hang on to her and see how she did. A picture is so deceiving. I do like #2 and #3 over #1.
I would not get rid of #1 either as I would wait and see how she does. How old are these heifers. If you told this, I somehow missed it.