Neuroscience is a hot area these days, and schools that have a program in neuroscience announce it in big capital letters, so it shouldn't be tough finding a program. Finding a particular lab, however, is another story and the best option is often applying to the best program, because she will need education in broad areas of neuroscience to do any future research. My training at Hopkins was all over the place but the professors were really good. I wound up doing my early research in a lab that I really didn't like but from which I learned a lot of basics. That being said, if she found someone doing Alzheimer's research and he wanted her in his lab and was a good teacher, then great. Graduate training is an apprenticeship of sorts, in that you learn a lot about a certain area of science directly under the professor's supervision. But that may mean that she learn a lot about molecular biology, not Alzheimer's. You need to learn a lot of science before you can apply it to a problem. Most people in the sciences go on to do fellowships to concentrate on particular problems. And there is a chance that she may find herself much more interested in a different, also important, problem.
Many medical schools have excellent neuroscience programs these days, and the problems they address tend to be more clinically-related.
Maybe the quickest way to find Alzheimer's researchers is to do a search of papers in that area, and see where the authors are from.
Here is a list of graduate programs in neuroscience for the Society for Neuroscience. I do not know how inclusive it is.
https://my.sfn.org/Directories...rov=&country=&type=8