I'm not important enough....

I'm so heart broken. I've worked so hard the past five years to earn my bachelors degree. I just told my mom when the ceremony was and she said that she would try to come, but she has to baby sit my sister's kids, because she does that during the week. I just don't know what to do. There will be many days to watch them, but im only graduating once. And ive worked so hard for this.