They recognised Willow raised the alarm with police at 10.30am.
Nicola appeared to know this route very well and shared pictures of her previous walks on social media.
In November, she shared a selfie while walking along the river and wrote: “A very foggy cold walk this morning, not a day to forget your gloves!
“Bit Spooky too! Set me up for the day though and Willow had the best time”.
Nicola’s partner, Paul Ansell, made an emotional appeal for help, saying yesterday: “We need to find her. She’s got two little girls that need their mummy home.”
Ch Insp Chris Barton, of Lancashire Police, said yesterday: “Nicola has now been missing for two days and we are extremely concerned about her.
“Firstly, if anybody saw her on Friday morning and has not yet been spoken to by police, or if anybody has any other information about where she might be, please get in touch with us straight away.
“Enquiries are very much ongoing and we have a team of detectives working tirelessly to establish the circumstances around her disappearance, in addition to a large team of police officers, partner agency and volunteer groups on the ground searching the area around where she was last seen.
“We are following a number of lines of enquiry and are keeping an open mind at this stage about what has occurred.”
