You're in no position to question what He does
Sure I am... because one time I asked him to cure my Mom's cancer... and she died.
No God. And we are all better off for it.
Death is inevitable, we are not immortal. Sorry your mother passed but God doesn't grant all prayers and He has His reasons for all He does. At times we don't understand but we have to trust in Him.
I've lost people very dear to me, I've never blamed God, I understand that is life (or the end of it) but they were not killed because they might be an inconvenience, might be a hindrance or simply unwanted. There is something wrong with a society that allows for that and if you support it I have a feeling I know why God didn't answer your prayers
The last sentence might come off as harsh, but it is wholly Biblical. We are free will humans. We have the free will to push God away. Since we are actually made in His image, He too can push us away as well--and at some point, He does and He will.
Much is made, for example, about "submitted marriage" and what is a woman's obligation to her husband in Christianity. But the Bible makes clear that if a husband abuses his wife, God will NOT EVEN HEAR HIS PRAYERS.
And that is about as serious as it gets.