Which is how I recall the second movie ending - after Janet gave her the healing touch (both hands on the face and a motherly hug) and calmed everything down.
In the after-credits scene for Ant-Man and the Wasp, they were working on helping Ghost (IIRC, getting some Macguffin substance that helps her, from the Quantum Realm) when the Pyms all got Snapped and Lang got trapped Down There.
I didn’t take that as being specifically to help Ghost - but I could be wrong.
Oh, and…
They apparently did “fix” Pepper Potts, in Iron Man 3. At the time, I presumed that Stark was just fixing the uncontrolled-explosion part of Extremis, but by this point, it kind of seems like, if they were going that route, they would have followed up on it by now. Especially now that we have seen Potts doing superheroing… by wearing a Stark suit.
They also did ‘fix’ the reason Tony needed the magnet in his chest - by pulling out the shrapnel.
Yes, they did explicitly refer to their “ghost friend” during the quantum realm post-credits scene. Many copies of it up on youtube.