A few things. No need to say anything except "our budget is too long in the red and I am cutting back, effective immediately." No further discussion is needed. She is an expense - net revenue loss - and the gravy train stops today.
If she squeals about it you will have to man up and not cave in; it's the pleasure/pain principle for both of you. And if it gets worse, so be it, the status quo sucks, according to you...and at least you're doing something to fix your problems.
Her: Once the pleasure of sitting around all day every day not working is eclipsed by the discomfort of sitting around all day every day with no phone, internet, and cheetos, she will come to a point where working is less painful than being a couch pig with no toys or a full trough.
You: Once the discomfort of her screeching in your ear as if she is incapable of working (sorry but I am unimpressed by her claim of depression, in the absence of you saying she's doing a damn thing about it; as others have posted here, self esteem is rooted in actual accomplishment...as long as nothing is accomplished, esteem stagnation will continue) is exceeded by the pleasure of her additional income streams in to the household budget (as if you'll ever see any of it), then your pain will diminish.
I understand you're falling on your sword cos you don't want to hurt her, but you fail to see you ARE hurting her by enabling and fostering her adult dependency - a completely untenable life choice these days. She needs to grow up, and frankly, so do you. She's not a child, and you're not her Dad, so lose the silly games and allow the sunshine of reality to give you both a fresh look at your lives.
"Personal density is directly proportional to temporal bandwidth."