@Background Pony #594F
Something happens to her in the future that makes her hate cutie marks, so she travels to the past to try and eliminate them. She’s foiled by the Mane Six, and having burned through her one use of the time travel spell, she creates the curse to prevent the Sonic Rainboom.
That would make no sense, the synopsis for the finale say that starlight glimmer obtained a spell what ch could change equestria forever and it’s up to the mane six to stop her, it’s like as if she was born before the events of the season 5 premiere and that she has first learn to time travel just for revenge.
This would be huge if it’s true. Personally I think it would be better if they Mane 6 don’t find out in the finale and it’s only hinted at to the audience so it’s very ambiguous even to us. We then don’t get confirmation until the baby is born. When Shining Armor and Cadance (who haven’t met the future Glimmer yet) name her Starlight Glimmer. I want that to happen just for the reaction of the Mane 6, it would likely be the greatest moment in the show.