Another indie author has stepped forward for a cover critique. I would like to welcome Marla Madison and her book 'She's Not There' to the blog. Side note: I make reference to Marla's son in the critique because she had mentioned him in her original email.
Here are the comments/suggestions I have after studying your cover. Please bear in mind that this is one person's opinion, but remember, too, that I am not your friend. Our friends are sometimes too kind and kindness doesn't always help us grow as artists, so it's helpful to get some 'real' feedback sometimes.
All the text is difficult to read, including the title. You never want to make someone struggle–even for a second–to be able to read the title of your book. YOUR title especially, is too strong to let it get bogged down in the design. If you are married to your imagery, then I would suggest reworking the placement of the title; perhaps putting a colorblock of some sort behind it.
The illustrations of the women are very cartoonish, which I think does a grave disservice to the message you are trying to convey. They have an almost "Scooby-Doo" (or some similar cartoon show) quality. It's a serious topic and a serious book and it needs to be portrayed as such.
The sticker bush is probably the strongest piece of imagery on your cover, however, the drops of blood, especially because they mimic your text color, are extremely distracting. The sticker bush illustration and the women ghosted behind do not 'match' and the styles are fighting each other.
If you are deeply attached to your cover imagery, then at the very least I would suggest you scrap the outlines of the women and try to rework the title to stand out against the sticker bush. They women are bordering on the comical.
So, I am afraid I agree with your son on this. Here would be my concept suggestion and your son would be able to throw it together for you with relative ease:
I love the idea of the ghosted silhouette, but how about if it was just one woman in a trench coat (with the high collar), facing forward, in shadow and seemingly melting into a grayish fog around her? If you start with a photograph, silo and flatten it so you have distinct (and very detailed) edges, then do everything in tones of soft grays, and you'll get that sense of someone 'disappearing' and it will convey mystery and jeopardy in one fell swoop. You'll also be able to really beef up the title.
I hope this helps!
Link to Marla's book on Amazon: