Personally, I wouldn't bring in the animal control people. You just never know what will happen. I don't know your area or laws, and some animal control will simply bring the kittens to a vet or a shelter and the vet or shelter keeps them for the three or seven days or two weeks before finding them homes - and if they haven't, then the animals get put down. If that's the way it works there, then I guess they have a fighting chance of surviving where they may not there given their living circumstances. It's a difficult choice. But my feelings are pretty strong - never trouble trouble until trouble troubles you. I wouldn't call animal control.
Get some rest - you need it! Mama's caring for her kittens now, so she's not in heat. We didn't trap the mom cat here until she'd raised the kittens (until we were sure they were 12 weeks old). Then we trapped mom AND the kittens and got them all spayed and neutered. That is something you can consider... as long as mom cat is "guarding" under the trailer, it would seem she's got a family. If so - the kittens will turn up in 4 - 6 weeks when she starts teaching them about life.
Then you can feed them too, and stops by your place will become regular enough that you can then work on trapping the whole family one at a time.
After 12 weeks, they don't need mum anymore, and she'll send them packing (likely) anyway.
Now - get your rest! You don't need to make any decisions today.