Allow your plants to veg a while ..from seed[ about a month] take cuttings from each plant...[3 from each]
Flower one of the clones from each mother plant and allow the others to veg some more...
The flowering the clones will tell you what sex the mothers are and thus what sex the clones are in the veg room[which are now a bit bigger]
Now you have discovered what plants are female...and can flower the clones you have already taken...plus you can discardthe males and never worry about male plants again!!!
Simply continue to take cuttings your favourite mother plant[this will save you space coz you've got only 1 plant]grow the clones and flower them.
Flowering clones makes better use of the space because they are all the same size ,all are short ..and you are garaunteed females!