The actress, 33, who played Lydia Chambers on the soap, welcomed the newborn after she and her husband Dan Acraman, who she married in 2022, welcomed their first in 2023.
Passengers were denied access to their allocated seats by Avanti West Coast staff on Saturday so the TV stars could sit together and have a carriage to themselves.
The actress was known for playing barmaid Nona Willis at the Rovers Return, but left the soap after 10 episodes because she struggled to understand the accent.
The actress, 36, who played Nicola Rubinstein in the soap, was stalked and terrorised for two years between 2018 and 2020 by a man who called himself her 'personal grim reaper'.