There are many options for a single mother to get grants for Higher Education. The first and most important step is to submit a FAFSA Free Application for Federal Student Aid. This will qualify you for grants that are income-based such as the Pell Grant and also determine eligibility for many other grants.
Depending on your state of residence there are wide variety of federal programs available to students. Pell Grants and Perkin Loans are two of the most widely know programs. If you are a veteran or work for a particular company there could be additional monies available.