2.5 yr old scared of the dark

tl:dr, my 2.5 year old had a screaming meltdown half an hour after I put her down because the dark is scary.  She has a nightlight and twilight turtle already.  I put a dim lamp in there but I'm afraid the light is keeping her up.  Now what do I do?

C has never had a problem sleeping in the dark, ever.  She actually usually prefers it darker so there are less shadows.  She has a small nightlight and a twilight turtle that turns off after 30-45 minutes.  Due to the holidays, she's been all over the place for sleeping.  A weekend in Canada with DH, and then last night at my MIL's.  Last night she slept in a pitch black room with her little brother.  His crying at 3am woke her up, and I'm wondering if the disorientation, darkness, different place, cot instead of bed, etc spooked her.  She went down fine, but as soon as the twilight turtle turned off she was screaming crying, even after I went in the room, because the dark was scary.  I brought in a dim lamp to leave in there, but it's been a half hour and she's not falling asleep.  She is intermittently calling out for me, but doesn't seem upset.  I'm worried that the light is keeping her awake.  So....fucked either way?  Scared of the dark so won't sleep, too much light so won't sleep.  This sucks.  What the hell do I do now?  Any advice?  See if it blows over after we're back on our normal schedule?