Theories

As a custodian Robert Zykewski would have had both means and opportunity to rape/impregnate Lilian having access to patient's rooms
In this time period custodians also doubled as handymen giving him access to tools
If Zykewski raped Lilian and Lloyd witnessed this attack this would explain why Lloyd randomly attacked Zykewski
If he raped Lilian and found out later she was pregnant and then attacked her per the scenario in the Lilian theory scenario #1 then she could have gone on to deliver this child either peri- or post-mortem

A normal autopsy uses one attending doctor and takes 2-4 hours to complete but Lilian's autopsy had three attending doctors and took 11 hours to complete lending way to scenario #2 in the Lilian theory
After being raped by Zykewski and becoming pregnant Lilian then goes in to labour and delivers said child
As is common in this time she dies in child birth
To cover up the fact that one of their own employees, or the fact that one of their patients was impregnated while in their care, the three attending doctors along with the head of the facility (DR signature of autopsy) decide to cover up the fact that she has delivered a child
They then proceed to stage a murder and cover up the pregnancy by stabbing her 13 times in the stomach and other areas of her body, also hitting her on the head with a tool
In this time an orphaned child was commonly named after an attending doctor, George Smith was an attending
George Madson could have been said child leading to the Madson theory