She's just calling. She'll calm down as soon as she stops calling.

Very long shot, but if you happened to know anyone with a neutered male who wasn't done until he was an adult, he just might do the trick and put her off call. Otherwise, there is supposed to be something you can do by sticking an appropriate object up her you know what, but I don't know what that object is or where you would get it from, and I wouldn't fancy risking it anyway. Bottom line - earplugs for a few days. And by the way, she will do anything she can to get out, probably including jumping from an upstairs window. The good news is that if she does get out she is not very likely to get pregnant at this stage, but of course you can;t absolutely guarantee that and in any case she might neglect her kittens.

Liz