Hello George
well i went to the library and looked for the records on the I.G.I. Fitch for Lancashire,there is no entry for a Louisa born in Liverpool.I also looked under any miss spelling entries,their wasn't a single Louisa among the many names.
I also looked for the marriage of Jane & William in Cheshire and Lancashire. With no results at all,so thats why you cant find the records on the net.They are not on the I.G.I. I don't think the on line are compleat anyway.The only thing i can think of as to why the are not on the original records is.That whatever church they used didn't allow access to the registers,you could allow for one missing entree but two from the same family would be strange. Even if they never married Jane & William should be entered as parent of Louisa.If she had been there,some religions like catholic i believe were one church that didn't allow access. Then again if you searched every church and chapel in liverpool & Chester at the chester archive. You still might not find them cos they might have married in Manchester or Stafford :-\So now we are all lost in the fog

Celia