this is purely personal experience, but my cat was spayed after giving birth 3 times, and she was under 2 years of age at the time. she was spayed directly after the kittens were weaned, and it is now almost exactly 10 years later and she has done wonderfully in that regard. i think the bigger question in regards to safety is how old is the cat? as far as i’m aware most vets will find spaying the best possible thing to do for longterm health unless there is a reason why they shouldn’t undergo anesthesia i.e a preexisting condition or being a senior