But she sees that black cloud hanging over everything. It's her black cloud, and it's not your responsibility to try to protect her from it. She's a grown woman. Give her space, and let her deal with it.
Everyone who is Christian or was raised Christian has their own take on it. As you said, it's a journey of awakening for you. If her brand of Christianity works for her, great. She has no right to impose it on you. Not any more.
By the way, history of "the devil," short version:
In the beginning, in Genesis, there is no Satan. There is a serpent. This serpent was a common symbol of Asherah (and some other Mediterranean goddesses) of the time. This would have been apparent to the audience the story was first written for. The serpent symbolized wisdom and metamorphosis. (Moses carried a healing serpent carving during the exodus!)
Here is Asherah with snakes
So, at the time this story was written, Yahwists were attempting to overcome female power, and one way to do this was to discredit female deities. Of course, Eve was in communion with Asherah in the tree, they were both females. Trees of life were also common religious symbols at the time.
Asherah was also invoked during childbirth, so the final blow to female power was Yahweh telling Eve she would labor in birth as punishment for taking Asherah's fruit.
Next time a "devil" crops up is in Job. The Shaytan is a member of Yahweh's heavenly court. He is sent by Yahweh to destroy Job's life to prove to Shaytan that Job will still honor Yahweh when all his children, livestock and even his health are taken from him.
No "satan" in Eden, just Asherah. No great demon "satan" in Job, just one of Yahweh's own court.
Then in 2 Kings 1, you see a reference to Baal Zebul, the god of Ekron. Later in the New Testament there is a reference to Beelzebub (Lord of the Flies), which is a Hebrew derogatory nickname for Baal Zebul. By the time of the New Testament, Baal Zebul had been turned into a demon by the priests of Yahweh.
Another conflated Satan story is "Lucifer, who fell to earth," in Isaiah 14:12. Read in context, it clearly refers to an actual Babylonian ruler.
Isaiah 14 even begins by directing this taunt at the ruler of Babylon! It clearly says that.
https://www.biblegateway.com/passage/?search=Isaiah+14&version=ESV
Lucifer is Latin for the Hebrew word Helel, the Light Bringer, which was an epithet, or nickname, of this ruler, who considered himself a god (as did many ancient rulers), and the son of the Goddess Dawn.
So, over the centuries, Hebrews and Christians have conflated Asherah (the serpent), the Shaytan (member of Yahweh's court), a Babylonian ruler (the Light Bringer), a god of Ekron (Baal Zebul, Beelzebub), to form this idea of Satan. Keep in mind also that in early Hebrew religion, there was no Satan, and NO HELL. The word "sheol" in the Old Testament means The Pit. There was no fire and punishment, no afterlife at all, until Persian religion influenced Hebrew religion in the 7th century BCE. Persian religion had a black/white, good/evil dualistic religion. This trickled down to Christianity hundreds of years later.
So, there's your Mom's enemy.