I will not deny your mother is a very good example of Christian behavior. She may very well be light years in front of me in her obedience to God. However if she worships the Sun, that particular act is unchristian and a sin. There are no sinless Christians. The bible says that if any man claim to be without sin, they are liars and the truth is not in them. I may very well sin more than you mother but how relatively good your mother is, is not the issue. I would not even suggest you tell her to stop or show her scriptures that forbid idol or object worship. I simply saying it is wrong, and that it is a very seldom practiced by any Christians. I doubt your mother worships the sun anyway. Worship, is based on the words worth ship. It is to acknowledge the worthiness of a thing (usually a divine being). The Sun deserves no credit for anything. It is harmful to just about everything, even things it is also a benefit to. It does not care about you, it is not "blessing" you with light (it is simply burning.
As for parallels between faiths. Since faiths generally answered the same questions, have actually copied other faiths intentionally or at least borrowed from them, and they deal with the same issues of course they would have similarities. That is realty irrelevant. To form an argument you would have to show the more evidence exists that the story of Christ was fabricated out of other myths. I have seen TWO professional PhDs do this exact same thing. The atheist was so embarrassed by the theist I actually felt sorry for him. If you want to see it and will have an open mind I will dig up the link to the video.