Re: Bed Time Vocalizations??
My kitty would do that, but not only at night...it was almost any time she left my bedroom and walked into the hall. Granted, at the time this happened, my cat was around 19yrs old and probably experiencing a little bit of kitty-alzheimer's or dementia. If I called to her, or poked my head around the doorframe so she could see me, her meow would change from distressed/mournful to a happy 'oh, there you are!' sort of sound and I'd either carry her back to my room or she would toddle on in herself.
When your kitty meows, try calling her to your bed so she may lay/settle down sooner rather than letting her walk around alone and cry. One thing you really don't want to start, is letting her learn that she can train you by meowing and making you come to her, giving her attention. Even if it is 'bad' attention (scolding) it is still attention in the cat's eyes.
Another trick you may wish to try is to give her a rousing good play session to tire her out before bed. Drag a string, toss soft toys to/over her or use a laser light for her to run and chase the dot.
Best of luck,