my mom paid for schooling for my brother and myself. I went to BYU-I and NAIT, and my brother went to U of U. She didn't do it because she felt she had to, she did it because she wanted to. Even being a single mother most her life, and after getting married and being told her spouse (who adopted my brother and i) wouldn't help pay for school, she still did it.
It's definately a choice for you to make. I don't think one decision is better than the other, just make sure if you're helping, you do it because you want to, and not because you feel you have to.