No, there are no shortcuts. But you don't need to work for 10+ years to get into a PhD program, and clinical/counseling experience won't help someone get into a developmental psychology PhD program - which is a research focused program. I don't understand the advice to get an MSW either - that might be helpful for a CLINICAL psychology degree, but not for a research-focused degree. Most people getting into PhD programs nowadays have 2-5 years of research experience before going in. In fact, your mom's 10+ years of experience with analytical chemistry (assuming she did research in the field) will be helpful because she can prove that she's done research and she likes it.
The 'work experience' you need to get into a PhD program in developmental psych is research experience. You don't need to have done it full-time for years, either, although that helps. Do you live nearby a large research university or some research labs? Your mom can look for lab manager/research coordinator positions if she needs to work full-time. Many psychology labs need a research coordinator, but she should also look at schools of medicine/departments of psychiatry, schools of public health, and even hospitals and independent research centers. Her years of experience as an analytical chemist will help because even though it's a different field, she knows generally how research works.
While she's doing this, she should also take some classes. The best thing to do would be to take graduate psychology classes, but she will probably need to take undergrad classes first. She doesn't need a second bachelor's degree; she just needs the coursework. She'll need to take introductory psychology, research methods, intro to statistics, 1-2 psychology lab courses (psychology of learning is my recommendation, given her research interests - cognitive psychology is another one she could take), and undergrad-level developmental psychology. If she can take classes in child psych, psychology of education, and advanced statistics, she should.
After 2-3 years of research and getting the required coursework she needs, she'll probably be ready to apply to a PhD program.
Your mother may also be interested in school psychology. She can do research with that, but it would also give her a license/certification to work in the schools. She could specialize in working with gifted/exceptional children.