Cover a plant in multi plant setup?

I got a plant in flower a month. Its pollinated and just showing seeds. I got 5 clones going. I was wondering what if i kept the whole setup of 1 big plant and 5 clones all under the same light. Flowered for 12 hours all of them and then at the end of 12 and 12 put in a mh conversion bulb and put a black platci bag over the big plant and let the clones keep vegging. The clones are so small and i wish i cud veg them more! ANy idieas on how to do rhis? I cant just move the big girl out they are in a dwc!