If she suicided and you mean to say you don't think she did right, I agree with you – life is so short and precious and alone, so we should try and try to live it at the best; however we cannot rightly judge her unless we are in her shoes (that obviously is impossible to do).
I'd never suicide for any who makes me suffer, even my boyfriend, because I value life too much. But I think I'd accept to die in order to save his life – this would be a very extreme case anyway.