In the first season, Episode 9 "DNA Mad Scientist". It can be misunderstood what the crew is precisely doing, what getting their eye fluid extracted in order to obtain maps.
They are indeed looking for a way to get home. It is not simply to know where home is. It is to obtain a path/route that will allow them to bypass any and all Peacekeeper territory, outpost, colonies, etc. They want this because every single one of them is wanted by the pesky Peacekeepers.
So in answer to your question, yes, Zhaan could have asked "where" the Delvian home world was. Problem would have been in "how" she was to safely make her way there.
Hope that helps!