You Would Think We Would Know

So, with Ellie being baby girl #2 you would think that we might know how to get her to sleep through the night consistently, but noooooo, of course not. We had her sleeping through the night somewhat before our cross country move. Then we got her sleeping through the night for a few days just before Nana came. However, with those two brief exceptions, we have been up 1, 2 and even 3 times a night. There isn't any rhyme or reason to it, just random waking up that ends with 4 tired and grouchy people trying to function the next day.

Do we always feed her? : Often, but not always
Does she wake up the same time every night?: NO
Is she teething?: Sometimes yes, sometimes no
too hot, too cold?: No and no (generally speaking)
Does she get special treatment when she wakes?: Only if you consider "half awake parents and a crying sister who hates being woken up to baby cries" special then yes
Have we tried alcohol?: Nope, and not gonna

The only thing we can think of left is letting her cry it out, and keeping her to a set schedule. This means Lizzie will be bunking with us since she can't cope well with non-stop sissy cries.

Any other good ideas??? (not rhetorical)

If not, pray :-)
Thanks!