The 26-year-old woman was pushing her two-year-old son in a pram and walking with her nine-year-old daughter on a zebra crossing in Furtherwick Road, Canvey.
A blue Ford Connect van was in collision with the mum and girl.
The girl suffered a broken jaw and broken ankle.
The woman suffered injuries to her ribs, bruises and cuts. She pushed the pram out of the way and the toddler was uninjured.
A 37-year-old man from Canvey was arresteHe was released on bail until December 4, pending further enquiries.
Police are appealing for witnesses who have yet to come forward. The collision was near the Rio Bingo hall at about 6.45pm on Monday October 31.
Contact Pc Victoria Harris at Chigwell Roads Policing Unit on 101 or firstname.lastname@example.org