What to Do With a Mother Still Nursing Kittens
A mother cat can be spayed without it interfering with her milk production. You can either trap the nursing female without her kittens and return her to them as soon as possible, or you can attempt to trap the whole family together.
You may also want to wait until the kittens are old enough to wean, typically at 4 to 6 weeks. This is also when you will see the mother cat bringing them out, thus making it easier to trap them with her.
If you catch her kittens, the mother will be attracted by their calls if they are placed in a covered cage just behind the trap. Similarly, kittens will be easier to trap if a captured mother is placed in a carrier behind the trap. Never place a kitten inside a trap as “bait” for it’s mother. It will be unable to defend itself from any predators who may find it.
If there is a possibility of any kittens being left behind in the wild, the nursing mother must be released to care for them 10 to 12 hours after surgery, but only once she is completely alert and clear-eyed after anesthesia.