The whole Sindel retcon has people fuming (those who care about the story). I like the story and all, but a lot of them are upset that Sindel has been retconned to have always been evil. I get their argument, but in every game (specifically the ones where she was cast as aligned with the good side), her design never matched that of heroine. Nothing about her had the vibe of a mother, wife, or even queen. She came off as a temptress who was cold, callous, and evil.
That pretty much messes up the narrative of her sacrificing herself to save Earth Realm, but I think that can be fixed. Jerrod married the real Sindel and she gave birth to Kitana. This Sindel sacrificed herself to save Earth Realm from invasion because she received a message from the elder gods, Argus, Delia or whoever about the future. After she sacrificed herself, her essence or whatever was preserved. What about current Sindel? Well, instead of having her be simply a creation of Quan Chi, she was created by Quan Chi under the order Shinnok, Kronika, Cetrion or whoever. The clone taps into the real Sindel's essence, which would allow Shao Kahn to invade Earth Realm. The side effect is an internal struggle within the clone between real Sindel's essence and Quan Chi's sorcery. The clone betrays Jerrod and being distraught over Jerrod's death causes Sindel's essence to takeover and again commits suicide. Fast forward to MK9 and Quan Chi resurrects Sindel again except its the clone void of real Sindel's essence only Quan Chi's sorcery. She isn't needed for Kahn to invade Earth Realm as the elders allow him access. Sindel is the conduit to wipe out most of Earth Realm's warriors as she does in MK9 until Nightwolf engulfs them both and she becomes a revenant in MKX.
To take care of her hero role in the 3D era is Argus/Delia giving Sindel's essence a host body to aid in stopping Onaga and preventing Armagaddon.