I need advice from all of those involved in catching strays/ferels...

We have an empty house beside us. There is a momma and 4 kittens living under the porch there that we, and the neighbor on the other side of the empty house, have been feeding and looking after. I think the momma is my Turbo's momma...and she is pregnant again. The kittens are about 4 months...anyway, my mom-in-law has a contact at one of the local shelters. If we can catch them all, they will be spayed or neutered, basically for free, and therefore breaking the cycle, even if we do put them back outside which I would prefer not to do but...

So, the neighbor on the other side, Tim, has atleast 2 of the kittens eating out of his hand, they wouldn;t be hard to grab. Momma is starting to come around a bit. She doesn;t scurry as far away when we go out to feed them but I'm really not sure of the best way to go about this. I don't want to grab the kittens and then have the rest disappear because we scared them. I would like to find them all homes and I'm working towards that but for the time being, any suggestions would be greatly appreciated...thank you! And I have to say that those of you who do this on a regular basis..you are my heroes!