I claimed the wrong dependant child, does amending the return cause a delay of refund for the person who should have actually claimed the child?

[AmyW]

No, the person that should claim the child will just need to print, sign and mail their tax return this year. They will just be unable to e-file.

If you want to file an amended tax return after IRS accepted your tax return due to accidentally claiming the wrong dependent, then you will want to wait until your original tax return is processed by the IRS. If you are receiving a refund, you should wait until the check is issued. Amended returns must be filed by mail.

To amend a 2016 return, follow the steps in the article below: https://ttlc.intuit.com/replies/5114064