Can i cancel a refile? i added some child expenses but it looks like the changes have no impact on my return.

Unfortunately, if you have already submitted your ReFile, there is no way to cancel it.  The only option is to submit another ReFile or wait until you receive your Notice of Assessment and submit an adjustment request.  Please see the following FAQ for instructions on how to submit an adjustment request.

https://turbotax.community.intuit.ca/replies/2647992