As James' father is apparently deceased by time of marriage, I tried to chase Emma's family.
No idea from the marriage date how old Emma might have been, but in 1841 I can find only a couple of likely Emmas with father John Johnson.
I'd expected to find them further up the Lancs coast, possibly in the Southport area, but are either of these any help:
An Emma J b. 1825, and on Kinsey Street Congleton in 1841, with father John and mother Maria - but he's a labourer.
An Emma J b 1826, and in Ashton under Lyne in 1841, with father John and mother Martha - but this chap's working in the cotton industry.