if its legal its up to the hunter...I wont say what is ethically correct because a chicken killing coon needs to go down and if its got babies so be it....same for a coyote.....now if I am out just hunting bob cats for leisure I am probably gonna pass on a bobby with kittens.....thats just me.....bear you only get one tag so really you cant legally take a sow and then humanely take her cubs so from the legal perspective we are hands tied and the choice is sort of made for us....
If you are hunting for meat take whatever you choose and can feel comfortable with because truth is if its human over animal from a survival standpoint its mainly the animal rights people that will guilt you into believing what you did is wrong.....in other words if i was starving and all that presented itself was a "baby" critter...baby critter is gonna go down...its then about my existence.....
really ethics are individual ...