How to Help Others Appreciate Something the way That You Do
The woman in question did come back, as a villain, who also turned out to be the mother of one of the main characters, and redeemed herself with the help of her ex-husband. He was a normal man, played by Kyle MacLaughlin, who would transform into a vile, evil, super strong creature called Mr. Hyde (thank you, public domain laws), but because Agents of S.H.I.E.L.D. didn’t have the kind of budget WandaVision or Loki later got, his transformation consisted of minor facial appliances, a wig, and a funny walk.
That was before the season where they were in space, the season where they were in the past, or the season where Coulson was no longer Coulson, but was still Coulson.
Someday there will be a documentary about that show. It will be like Jodorowski’s Dune, only this time the crazy improbable project actually got made.