First point…EPS is an archaic file format.
Second point…I’m not sure what this has to do with InDesign.
Well archaic or not it is what they use and it is two users one uses illistrator to do something and the other uses InDesign to make changes. I'm not sure if that matters much but when my Mac user makes changes she has to save a new version and is not allowed to make changes to the original that was created by the other person. It seems to be the issue of going from PC to Mac on the network share drive that is the issue. I just want to know if anyone has seen this or what the solution would be.
InDesign does not open or save EPS files so my second point still stands. It sounds like you have some serious user error going on there.
There is lack of coherent information regarding your question.
As far as I can figure out, your user on the PC uses Illustrator to create an EPS and the Mac user wants to alter this EPS using InDesign?
How exactly is the InDesign user planning to do this? As Bob pointed out, InDesign can PLACE an EPS (or other image format for that matter) but InDesign cannot make changes to them because they are images. Yes, the InDesign user could crop the image, but to alter the image they would need to edit it in Illustrator (or Photoshop depending on the format) InDesign is a page layout application not an image editor.
I can only think of 2 possible ways that this makes any sense:
One is that it is possible to copy and paste a SIMPLE vector paths image from Illustrator into InDesign. You can then do some basic altering of the paths, etc. But this will only work with very simple graphics. I believe the limit is only 500 points (but I could be wrong about this number) that can be pasted as editable in InDesign.
Larger than that and the image will only paste in as a solid uneditable image. But then this begs the question: since the InDesign user would need to have the EPS open in Illustrator to be able to copy & paste into InDesign, why don't they make the changes directly in Illustrator?
Also, the vector paths that are pasted into InDesign have no link back to the original file so of course they can't save the changes and alter the original file.
Another possibility is that they are PLACING the image in InDesign (as well they should since copy & paste doesn't create a link to the original file) and then they are using the LINKS panel in InDesign to edit the file in the original application (i.e. Illustrator) when they edit and save the changes in Illustrator and close the file and return to InDesign the EPS should be automatically updated in InDesign. If this doesn't happen automatically you can manually update it via the LINKS panel.
Again, we don't know because there isn't enough information about what they are actually doing. I'm not sure of your personal experience with these programs and it sounds like you are receiving incomplete information from your users. Like Bob said, "It sounds like you have some serious user error going on there."
You mentioned a network share drive and "She has been renaming this as a work around but that is a waste of space."
So somehow they are managing to accomplish their task? How are they doing this by just renaming the file?
Your users need to give alot more information about how they are doing this.
But looking back I wonder if they are editing the original via the Links panel and then having trouble saving to the original name?
If so, that should have been clearly stated as the issue. If that is the problem it is probably a network server issue and not an inDesign or Illustrator one. Can't help you with network workflow issues. Perhaps someone else can find a solution?
But, please clarify the issues so someone can help you!