I'm only just watching the vlog (because Sarah and Chris, some people actually have to go out to work).
Anyway, I noticed that when they got to the Hawthorne Farm/pub place, Sarah mentioned that Isabelle put Jace's dummy in. She also said Esme was telling her a story in the car - meaning that Esme, Jace, Isabelle and Sarah were in the Mini. However, Jace's pram and Jace himself take up two seats, but Sarah's car only has four seats?
Chris walked from his car without the pram so it definitely wasn't in there either!