Marcus Caffery was told by dad David to keep his mum calm when she started having contractions in their living room while he went outside to look out for the ambulance.
But when David, 42, walked back inside minutes later, Marcus was on his knees delivering his own sister at 10pm on November 13.
By the time paramedics arrived all but the tot’s feet were out and the schoolboy was knelt with little Freya in his arms in Tettenhall, Wolverhampton, West Mids.
Incredibly, while medics finished delivering his 8lb 7oz sister Marcus moved over to his little brother Alexander, one, and calmly explained what had happened.
Proud mum Jodie, 38, and Freya were taken to hospital for a check-up but were discharged the next day.
David, a college caretaker, said: “I don’t think it’s really sunk in for him. We’re so proud of him.
“We couldn’t believe how calm he was.
“On Sunday morning Jodie woke me and said her waters had broken, it was about 7.15am. I phone the grandparents to have the two lads and took Jodie to the hospital.
“We were there all day but all of a sudden in the early evening the contractions stopped.
“The midwife said she thought it didn’t look like anything was going to happen and it might be best for Jodie to come home with me.
“The kids’ grandparents phoned as well to say something was happening at home for them. So we said we’d get the kids and drive back home.
“We were hoping that the drive in the car might set off Jodie’s contractions again so that way I could just whip round and take her back to the hospital.
“We got back, Jodie was watching I’m A Celebrity (Get Me Out Of Here) and I was in another room doing some housework.
“I heard her sort of shriek, but I thought there must have been a spider on the TV because she’s got a phobia. I went in there and the baby had started to come out.
“I said to Marcus to go in there with his mother and just talk to her while I phone the antenatal unit at the hospital.
“I explained what was happening and they told me I had to phone an ambulance.
“I needed to keep her on the phone but look out for the ambulance as well because it’s tricky to get to where we are, a sat nav won’t get your there.
“The woman on the phone from the antenatal unit asked if anyone was there to help. I said tongue in cheek that my eight-year-old was and she said that’ll be fine.
“I thought, ‘what?’ But she said to pass the phone over to him.
“I was darting in and out trying to look for the ambulance and check on Jodie at the same time.
“I went out once, everything was fine, went out a second time, no problem, but after I came back a third time Marcus was literally on his knees with his hands underneath the baby’s body.
“I couldn’t believe it. Apart from the baby’s feet, he had pretty much delivered her.
“A colleague from the college arrived and he helped out by going and watching out for the ambulance.
“The paramedics arrived and did a brilliant job. The gently moved Marcus to one side and finished delivering Freya.
“Then straight away he went over to his brother and started reading him a book and explaining what was happening. We couldn’t believe it. I couldn’t have done it.
“I’ve already told him he’s getting a large Christmas present and there will be stuff winging its way to him when we get paid as well. He’s already started making his list.”