It's ok to take cuttings from a flowering plant. You would just have to revert it back to the veg stage maybe a 20/4 or 24hr light schedule. I've read you can/should remove the bud sites so it can focus on rooting also. That part is theory to me as I haven't tried it yet.
Concerning cloning with no mother plant: you can take cuttings from a donor maybe a week before flipping her to bloom cycle so she can recoop from any stress. Then let your clones grow big and right before you flower those, take cuttings and repeat the process.