All 3 of those look healthy to me. Do you have an oscillating fan near them? That could help the stem strengthen on the first one but I think it's fine. I understand you've had them in 12/12 for a week, but I wouldn't start counting weeks of flower until they show you some little hairs. Then when you ask if they look good for, say, week 3 of flower, people will have the right expectations. They do always turn a little less green up top right before pushing out hairs, so you should see hairs really soon, probably before the end of this week. Mine take 7-21 days, usually 7-14 to show sex.
FeelinSpacey is right about the first one being small, but since it's already been in 12/12, I'd leave it in there (won't hurt either way). It's just one plant, it'll still give you a little bud, and you're going to have plenty more plants to leave in veg longer.
Does the first plant have drain holes? If you did give it a bigger pot it would get larger, but it'll flower out in that little pot just fine. A lot of what you're doing can be done a lot better but the plants should be able to finish flowering the way you have it.