Can anyone here guide me on feral kittens and all it involves, please?

[herding cats]

I have a mommy cat who brought her babies to me 4 weeks ago. She's tame and I'm sure she was once a loved house cat before she came into season and they tossed her. She's very young and I'm guessing this is her first litter.

I first saw her on my deck. She was hiding behind a flowerpot waiting for me to water, I'm guessing so she could get a drink.

I lured her out with food and real water and gave her love. She was tame and had obviously been loved once. Which was when I noticed she was a dried up recent mommy. No milk nor signs of recent nursing, but she had been feeding babies not long ago. She was skin and bones. Truly a starved kitty on the edge. I assumed she'd been giving her all to keep her babies alive, and they'd passed in the excessive heat, sadly.

I felt guilty for not meeting her sooner and did my best to provide for her from here out.

Then 2 days later I saw she was making milk and 2 nipples were being sucked. My quest to find the babies began. I crawled through brush, under out buildings and my deck. I kept coming up empty handed. She kept coming in each evening for food and water, but I had no clue as to where the surviving babies were.

Then the heatwave hit again and I was sure they'd die. I cried. A lot.

I was sure these never seen baby kittens couldn't survive out in the wild in these outlandish temperatures. My heart was broken for them. I just kept feeding and watering their mother, which was all I could think of to do.

Then, she brought 2 sweet kittens up to my back door. She meowed loudly until I noticed and responded. They were completely feral little babies. But, set out cans (they were tiny babies) and began trying to create some form of relationship.

This was a month ago. I can pet them (barely) when I feed them now, but I'd greatly appreciate help with how to make them more tame so I can take them to to the vet, etc?