You never add a dependent's wages or income to your return. You still claim her as a dependent and she has to file her own return. Be sure she checks the box that says she can be claimed on someone else's return.
If that is the only income she made she doesn't have to file a return except to get back any withholding taken out. If she does make more than $6,350 she has to file. That is for W2 income. If she gets a 1099Misc for the income then she does have to file a return no matter how small. 1099Misc is considered self employment income and is taxed differently.
The Online version is only good for 1 return. But you can use the same email address for 5 accounts. To do another return you have to set up a new account and new user name and pay any fees again.
How to start another return in the Online version
https://ttlc.intuit.com/questions/1894512-how-do-i-start-a-second-return-in-turbotax-online
