I've been to Lichfield Archives today and tried to look for those burials. They are definitely not at St Paul, nor could I find them at St John

I also looked for baptisms, and coudn't find any.
I did find the marriage entry for William and Amelia

26 December 1853, St Paul, Burslem by Banns - William Hackney (x), full age, widower, Potter of Burslem. Father: Thomas OAKDEN, Brewer.
Amelia Gallimore (x) aged 20, spinster, Potter of Burslem. Father: Francis Gallimore, Potter.
Witnesses: Michael ?Coines? (x) and Mary Heath (x)
I haven't had another look at FamilySearch since my return from the Archives. It might be an idea to try to contact LDS - if you're in the UK then their headquarters are in Sutton Coldfield - and try to get an answer as to the church from them.
And I think this is possibly Catherine's marriage in 1876
16 April 1876, Christ Church, Cobridge by Banns - Samuel Wright (x) 21, bachelor, Engineer of Gra???lly Buildings. Father Joseph Wright, Engineer
Catherine Hackney, 18, spinster, Servant of

? Road. Father William Hackney, Potter.
Witnesses: Thomas Richens and Ellen Richens
Sorry, the writing was not very good on this marriage entry!!!