Miss Rattan got up and followed her brother across the road to where the vehicle had come to rest.
"I saw the passenger and I heard the driver saying sorry. But I think the passenger had passed out by then."
She said the female driver walked away from the crash, but the passenger's legs were stuck under the dashboard and she had to be cut free.
Once free she kept "complaining" about her head injuries, Miss Rattan said.
The tenants of the damaged house were "supportive" of the car occupants and were helping out with the crash, she said.
The Fire Service used the "jaws of life" to cut the passenger from the crushed car, spokesman Jaron Philips said.
The car's passenger and driver were taken to hospital about 6am with moderate injuries, said ambulance communications spokesman Glen Taylor.