Sheila's mother gave her occupation as "nurse" in domestic service in Kelvedon Essex. Why was the birth in Newcastle then?
Many different scenarios could answer that question, unfortunately the one definite answer is 'that was where her mother was at the time' :-)
You'd need to track back and see where the Mum grew up, sideways to see where parents, siblings, grandparents, aunts and uncles etc were at the time. If that points to the Newcastle area then its likely that Mum became pregnant whilst in service and went back to Newcastle to have the baby where she had some family back up to help after the birth. She'd, for instance, need somewhere to go to when she left the hospital, employers in Essex would be unlikely to take her and an illegitimate child back into the household so she'd likely turn to a sympathetic relative.
Do let us know (I get ever so nosey!) if the second birth cert names a father. It 'could' have been the man Mum married a year or so later - if he was a sailor then its not beyond possible that he was docked near where she worked in Essex and that's how they met (or met up again if they both originated in Newcastle). He could have been at sea for some length of time and their marriage couldn't happen till he came back after the baby was born.
Just as an aside, what was on Sheila's marriage cert as her father's name? Was it the man her Mum married? Though that's not 'proof', she may not have known and if someone was your Dad for as long as you can remember, then he's your Dad. The genetics thing doesn't always count as much as the time and care given which makes you a proper parent :-)
Boo
