I do not think that you have missed anything.
The Mary Isaw is on RG10/4039 folio 53 page 10 Deansgate Manchester.
Thomas Miller Head 36 Painter b Manchester
Mary Miller Wife 34 b Scotland
Joseph Miller son 21! Bolt maker b Manchester
Margaret dau 5 b Manchester
Mary Ann 7 b Manchester
John 3 b Manchester
Thomas 1 b Manchester

Do you have any information on the Thomas that you are researching (birthdate? place of birth, etc.)