Well I don't think you need to wean her to stop it. Seems like that might make it worse. It may be a phase. My DD always used to wake up happy but she wakes this way from naps now quite often. I am really not sure why. If I am not next to her when she wakes in the am (we cosleep) she does this too and I totally understand it setting you off on a cranky path. She stops in the am once she sees me. As for naps, I have started talking to her very soothingly to distract her with questions. If I nurse her (a totally reasonable soothing method, she is capable of "self-soothing" too, btw) when she gets up cranky/crying from a nap, it makes her go back to sleep so I have stopped doing that. I just don't want to prolong the nap/nurse thing. So I talk to her about being cranky, is she still sleepy, does she want some water, etc, until she is calm and reasonable. It seems to be getting better. I think it's a process tho.
Sorry that wasn't very concrete, but I get where you are coming from. I have found in the ams that if I let myself get upset about it, that's not helpful. So I try to be calm and understand that she just needs a little transition time. I also have a bottle of water there for her and a book or 2 so that helps.