A timeline where Loki hit himself with gamma rays to try and get payback against the Hulk? The key thing though is it's not linear. The variant may be from birth (born a woman) and the branch happens immediately. Other variants may come from choices, like my initial point.
But let’s say our Loki is a tomato plant - it doesn’t matter how early a variation happen; if it produces a bell pepper, it comes from a different plant