I manually renamed one of my starting characters Ashley, which is a common name, but in a later game one of the crew members I got was named Ashley. I was just curious if the game adds names you manually enter to the list it pulls random names from.
No it doesn't.
Ashley is already in the default name list from the start.
If you do want to add names to the list, see this related question. You can also use the information there to open the
names.xml file and see the default list yourself.