If you are a single mother who wants to go to college, finding free grants for women is not difficult. There are federal government grants like the Pell Grant which are open to all US citizens. There are also educational grants awarded by state governments. And there are even women-only tuition grants awarded by charities.
In fact, if you enrol in a community college, women's college or historically black college, you will probably never need to look beyond the free grant money awarded by the federal government and your state government. All you need to do is fill up the FAFSA form online, then pass on the results to your college's financial aid office. They will ask you to fill up some additional forms for individual grants and scholarships, and you will be well on your way to getting most of your college education paid by the federal government and your state government (assuming that you are in the low income bracket).
Unfortunately, if you study at a for-profit college, your situation is more difficult. First, these types of colleges do not participate in many government grant programs. Almost all of them will be in the federal Pell Grant program and Stafford student loan program, and some will also be in the Perkins student loan program, but that is likely to be all. For-profit online colleges are even worse. Their students are not eligible for state grants at all.
The second problem with for-profit colleges comes from the way the federal government's college grant system works. FAFSA (DOE) decides the maximum amount of free federal aid you are eligible to receive. Let us say you are allowed to receive up to $7000 of assistance. However, your college gets to decide how much to actually give you. The DOE gives each college a lump sum based on certain factors, and the college chooses how to distribute that money. So your chosen college can legally decide to only give you $1000 and make you take up student loans to pay for the rest of your tuition fees.
The final problem is that for-profit colleges charge more in tuition fees. This is obvious, since they are a business. Somewhat less obvious is that their operations are not subsidized by the government, so their rates are less competitive than those of community colleges.
If you do not wish to end up in debt after graduating, you had best find and apply for the free money for college for women that is awarded by charities for women. If you are a black or hispanic woman, you should also look for free minority grants. Unfortunately, there is usually little use for you to apply for any federal grants other than the Pell Grant.
Those who do their homework can often find 20, 30 or even more free grants for single women. The problem is that most of these grants open and close their applications around the same period of time, giving you only two or three months to fill up the forms. If form filling was the only requirement, you would be fine. But often, they also require various documentary proofs, e.g. certified copies of your income tax return, certified proof of volunteer work, etc. They may also require essays and/or interviews. These are all things which need extra effort and time. To get everything done in such a short window of time, you need to make a good plan. You may even need to know which of these private grants or scholarships are not worth your time (e.g. too little money awarded, too little chance of success or too much effort needed) and dump them.
Basically, if you study in a government-subsidized college, you can probably get enough free grants for women from the government to finance your studies. But if you study in a for-profit college, you will probably need to find many private grants and scholarships to pay for your college education.