Hiya
In theory i'm supposed to believe that all people who commit suicide go to Hell, because i'm Catholic. But i don't think your mum's in hell, if she was a good person, lived her life the best she could, and loved her family.
I get that you're supposed to go to hell because you take a life that God gave you and it wasn't technically yours to begin with...etc, but people who are ill and dying, people who's entire family has been wiped out, people with mental health problems, people who feel like they're worth nothing, people who - in short - can't take anymore, and see no other way out. I really don't think that, in their darkest hour, when they need someone the most, God would turn his back on them. I think he would take them in his arms and tell them they're suffering is over, and it's ok now.
Most people can't help what life throws at them, and sometimes we need forgiving instead of punishing, for being only human, like God made us to begin with.
That's what i think anyway...