Yes, that is Jean. Just to save going over ground I have covered, I should add that she had an illegitimate child William Livingston in 1851, who subsequently lived with her parents Robert and Joan.
Then she had the child in 1848 who was the subject of the aliment decree. The father was William Maclachlan, a coachman in Edinburgh.
In April 1850 she was up before the court for "having a child in a rather private manner". It's a convoluted story in the Dundee newspaper. The father was alleged to be a coachman in Edinburgh (sounds familiar!). The child, a girl named Jane, was buried aged 5 weeks.
She married Edward Johnston in 1851 and they had the son registered with no first name in 1855. The birth record says they also had one other child, a girl, who was dead. I have never found that birth or burial.
I am trying to find the whereabouts in 1851 of the girl born April 1848 and the whereabouts in 1861 of the boy born 1855 and Margaret Whitton born 1858.