@ The Eighth Passenger - Ha ha, silly me. You are of course right about the 'baby Deacon' being born at some time AFTER Shaw and David have taken off from LV-223.
(I kinda forgot that fact due to various comments here and elsewhere in the past, which speculated on Shaw running into the 'Deacon' BEFORE she took off - which were all WRONG of course, as she was already away as you pointed out. I guess my memory lapse was influenced by that kind of thing when I commented in my previous post!
So yes, I absolutely agree now that Shaw might have bravely ventured back to the 'Lifeboat' for various supplies before she took off.