Emergency services were called to the St Marys home around 5:20am after the driver lost control on Monfarville Street, striking one of the home owners.
Roof racks were seen impaled on a tree outside the home.
Police stopped a woman nearby after she allegedly ran from the scene with her baby.
The woman was arrested and taken to Nepean Hospital for mandatory testing.
Both were uninjured.
Residents on the street said they were awoken by a loud “boom”.
“No brakes, nothing. It was just, yeah, just a boom,” one shaken witness told 9News.
A crime scene has been established and police have began an investigation into what led to the crash.
Anyone who may have information, dashcam or CCTV is urged to contact Nepean police or Crime Stoppers on 1800 333 000.
