You can still include the children as dependents on your tax return but you will have to print and mail your tax return, regardless if they amend their tax return.
See this TurboTax support FAQ for how to print and mail a tax return when using the online editions - https://ttlc.intuit.com/turbotax-support/en-us/help-article/printers-printing/print-mail-return-turb...
