I could try to make something up, but I'm -really- out of good ideas right now. What do you need exactly?
That's a letter, that unromanced Shepard gets after Horizon. What could it be for Ashley? I don't really know.
For Kaidan we took original letter as an example, but it was significantly modified, all the obvious romance hints were toned down and removed, We tried to make it look it as 'seamless' as possible. It's just a letter to a friend, a former CO, one he respected, one he cared about, one he had lost.
It never made any sense to me, why would Kaidan write his apologies only to someone who had bunked with him before Ilos.
From what I know, same happens to Ashley. Liaramancers, single mSheps and femSheps never hear from her after Horizon.