My char has adopted Lucia and she went to Breezehome as usual, but there she just stands by the fire and says "I can't wait" if I try to initiate a dialogue with her. I thought it might be glitching and would be fixed if I waited a day or so, but when my char comes back a day later the situation is still the same.

I found http://www.loverslab.com/topic/15400-resetting-hearthfire-npc-orphans/ with console commands to reset the quest etc. which fixed it for the OP, but if I try it I just end up in the same situation: adopting her and she standing by the fire saying "I can't wait". Does anyone have a tip on quest resets or the like that might work - or should I reload from an earlier save before adopting her in the first place (annoying as my char has done quite a lot since then - but it's even more annoying to have her as a zombie by the fire.).

On a side note, it's rather amazing how bugged this game is even after the official patches and using the latest unofficial ones.

EDIT: And the Creation Kit crashes if I try to load it with HearthFires.esm. Excellent...

Agree! Quite frustrating sometimes.
One of my two daughters (forget which) disappeared completely while we were living in Breezehome.
Solved by moving to Solitude. And I got my alchemy room back (bonus).
Breezehome is [censored].

It doesn't even help to reload from an earlier save. The same thing happens when I start from scratch and adopt her again. Tried three times in a row now.