A mh or hps can be used for a full cycle.

Do you have the widow and the seedlings in the same tent? From what I read it sounds like you do.

Plants need at least 12 hours of complete darkness to flower correctly. Lowering your lights over the seedlings will not make the widow bud. What you can do is take the widow OUT of the tent after 12 hours of light and put it somewhere else thats completely dark. I use a smaller tent for this purpose. The darkness must be COMPLETE and uninterupted.

Also try not to switch back and forth on the lighting schedule. Thats an easy way to make your ladies hermie.