No. But I do hope that Bethesda might do it. It's worth the shot asking openly on the forums. Even at the risk of all the potential flame I might get or people who do doubt it would happen. I love this girl and she makes me happy. So that's all that really matters to me. And even if it doesn't happen I will find some other way to propose to her. Without photoshopping, modding, or anything with a computer. But that's only if they don't.
I see, I just thought it was weird the photoshopping a dead body thingy

But, I think, it would be cool if Bethesda created a quest about marriage like the one in Fallout 3 (Rivet City), and replaced the NPCs with your names. And then you played through it with your GF next to you, and the NPC would propose to the other NPC just like you would with your girl. And then you turned to her, with that smile on your face and then you showed the ring.
That would be nice. Adding a small quest in this stage of development isn't hard. You should send an e-mail to one of Bethesda's staff.