The books tell us Jada's age is when nightmares begin. And in fact, she's had at least two in the past three days. Sleeping in a different place and having so many new experiences, I'm sure that's a situation ripe for nightmares.
What's happened is that a couple of hours after she's gone to bed, Jada has woken up screaming a piercing scream. Our strategy on crying and bed has been that if she's just plain crying, we'll let her be for up to 45 minutes, but if the cry sounds like she's in pain, we'll go in right away.
The nightmare scream is certainly much closer to the "in pain" cry. So our strategy here has been to go in right away and make sure she's not in any sort of pain, calm her down and tell her everything's OK, and then put her back into bed. Our thought here is that we've gone in and allayed our concerns that something was really wrong, and having made sure that's the case, we're going to leave her be.
Of course, going in and then leaving is guaranteed to make her even more upset, and in fact both nights she's had nightmares, we've gone and quieted her down, only to leave and have her erupt in even louder and fiercer crying. This crying is very difficult to let go, but we're holding our ground here, in terms of giving her space to learn how to get herself calmed down. These two nights, it's taken a good twenty minutes, and it hasn't been pretty listening to her wail like that, but she's eventually gotten back to sleep.
(By the way, if you're wondering how we know it's a nightmare, we don't. But we think it's a pretty good guess, because she reacts like she does when she's afraid, like when the doorbell rings or when she sees a leaf on the ground: clinging desperately to us, shivering, looking fearfully at the bed. Poor thing!)