They will each have to file their own return. Be sure and create a separate account or each of them.
https://ttlc.intuit.com/replies/3288574
Also be sure have have them indicate that they can be claimed as a dependent on someone else's return.
In the future you may want to consider buying the download version of turbo tax. It is usually more cost effective when doing multiple returns.
https://ttlc.intuit.com/replies/3301381
