Puppy Love - a dilemma!

I was on my way out this morning when I passed the house up the road, and there were two black Labrador puppies playing in the road! They were tearing a recycling bag apart, spilling its contents everywhere!
I stopped the car and thought at first they’d been abandoned, but then saw mummy labrador pacing behind the gate with no3 puppy.
I picked the puppies up and pushed the first one through the bars of the gate, while the second one started playing tug of war with the shoulder strap of my handbag. He was too tubby to fit through the bars so I had to drop him over the wall. 
Mummy was relieved to have them back, and they had a quick feed and escaped again through the bars of the gate! Obviously I was worried they would get squished on the road, but they didn’t and I stopped again on the way home as the owner had returned.
The owner immediately offered me a puppy free of charge as he couldn’t afford the vaccinations and couldn’t sell them without! So all day my head has been wrestling with my heart! 
Mr F thinks the owner will drown the puppies, so he rang the local dog charity, but they won’t take the puppies until they are twelve weeks old, and at the moment they are only eight weeks. So what to do? We can’t take all three and I’d worry about the ones left behind, but I don’t really want another dog, and can’t stop thinking about them.