I don’t think that you will be able to spay Wiggy a week after she gives birth. She will be nursing then. You would have to wait until the new litter is weaned for her to have the surgery.
One or more of her babies could certainly be her companion(s). Besides getting her spayed, you will have to get any future companion neutered or spayed. Then after a few weeks recuperation and time for the hormones to settle down, you can start the permanent bonding. It is easier to bond a neutered male with a spayed female, but you can bond same sex rabbits too. Any rabbits that you put together have to be spayed and neutered first. It only takes a few seconds of mating for a pregnancy to occur. You have to make sure that any rabbits who are old enough to reproduce are kept completely separate. They have even been known to mate through cage bars.
Any babies that you have will need to be separated before they reach 12 weeks of age. You could either end up with more litters if they are kept together or you could end up with injured bunnies if they start fighting when they reach puberty and their hormones come flooding in.