Does anyone have any kind words?

My mother ped away at the age of 64 Sunday morning. She had a number of things wrong with her internal organs. Things no one knew about because mom did not go to the doctor much in her life time. It happened with in a period of 2 days. It all started with being sick and then a cardiac arrest when she got into the ambulance. She was pronounced dead the next morning after being on life support all night. I have questions as to why this had to happen? Why did she leave us like that and so sudden? Why did she abandon my niece that she was taking care of since her dad died over a year ago? The whole thing is so sad. We had just celebrated her birthday a week ago and she had a good time. I know no one really knows what happens after death but, does anyone have a good idea? Is she in a good place and hopefully with God? I am just looking for some reurance. Sorry it is hard to loose someone you love so much and has always been your best friend.