Could use some really good advice please.

I think I really messed up initially starting my plants off. Below is my sequence of events. But any advice after reading I would greatly appreciate. For example, though I am in my sixth week. The plants are too premature to start on 12/12 lighting. SOLEY due to my ignorance of starting them off on 12/12 lighting. Should I just keep them at 18/6 now for another 2 weeks or so. And then flip them back into 12/12 to help me better determine the sexes. I am including a couple small picks of each plant sidd1 and sidd2. ANY advice would be greatly appreciated.

What to do next?
Sex of plants?
What not to do anymore?

7/29 germinated some white widow stock
8/2 seedlings, aprox. 2 inches in height, were placed in hydro garden with no nutrients with 12/12 8000lumens florescent lighting.
8/9 Hydro garden reservoir was changed and appropriate nutrients were added to start growth. Seedlings aprox. 6 inches in height but still with 12/12 8000lumens florescent lighting.
8/14 Hydro garden reservoir was changed and appropriate nutrients were added to start growth. Seedlings aprox. 6 inches in height but growth on branches forming nicely. Note again still with 12/12 8000lumens florescent lighting.
8/20 Hydro garden reservoir was changed and appropriate nutrients were added to start growth. Seedlings aprox. 6 inches in height but growth on branches forming nicely. Note again still with 12/12 8000lumens florescent lighting.
8/26 Hydro garden reservoir was changed and appropriate nutrients were added to start growth. Seedlings aprox. 7 (sidd2) and 8(sidd1) inches in height but growth on branches forming nicely. Note again still with 12/12 8000lumens florescent lighting.
9/1/ Hydro garden reservoir was changed and appropriate nutrients were added to start growth. Seedlings aprox. 7 (sidd2) and 8(sidd1) inches in height but growth on branches forming nicely. Note CHANGED lighting to 18/6 8000lumens florescent lighting.
9/5 Hydro garden reservoir was changed and appropriate nutrients were added to start growth. Seedlings aprox. 7 (sidd2) and 8(sidd1) inches in height but growth on branches forming nicely. Lighting to 18/6 8000lumens florescent lighting.
9/9 Hydro garden reservoir was changed and appropriate nutrients were added to start growth. Seedlings aprox. 7 (sidd2) and 9(sidd1) inches in height but growth on branches forming nicely. Lighting to 18/6 8000lumens florescent lighting.
Trimmed 4 shade leaves from top of sidd1
Trimmed 3 shade leaves from top of sidd2
9/11 Topped both sidd1 and sidd2. Or did what I think I am suppose to do. I took the most top region of leaves forming and clipped them from both of these plants.
9/14 Hydro garden reservoir was changed and appropriate nutrients were added to start growth. Seedlings aprox. 7 (sidd2) and 9(sidd1) inches in height but growth on branches forming nicely. Lighting to 18/6 8000lumens florescent lighting.

they look fine to me. they may have been larger if given more light, but no harm has been done. you could start to flower them if you wanted, or wait till' they get bigger, but their not too young. just keep up what your doing and you should be fine.

Any comment on the sex?

It is really hard to say on the sex. I would say let it go a little longer on the 18/6 if you are still on it and you can begin to tell a little more, then once you start the 12/12 it will begin to really show the sex. You want your plants to grow more than that too before you flower so you can get a decent amount of buds from them.