Right, that sound like a female cat in heat - probably with a Siamese mix in her background. Can you find the owner and ask them to keep her inside until it's over or at least get her fixed (she can call local pet shops and the animal shelter to get advice on free or very cheap neutering programs.) Meanwhile if she lets her little baby roam all over the place, there will be more kitties and probaly a bunch of cat fights in the neighborhood to keep everyone awake half the night.. I have two kittens now and they sound like 2 sweet little musical birds at night.