"Do you think my memories will sort themselves out?" You asked your sister, unconsciously wanting to be comforted.
A monotone and soulless "Yes" from your sister is your answer, caused by your powers, as they rewrite reality. The thing is, you never precised how they would be sorted out in your question, so you will slowly gain the memories you would have made if Jane and you really were born as witches, from a mother that's just as much a witch. In time, the memories of being an ordinary boy named Colin fading as no more than a temporary hallucination.
But at this point in time, you're very far from that. Your life as Colin still being the only thing you remember, although those memories start to have a slight sense of wrongness to them.