How do I switch accounts? I file both my children's returns and it keeps pulling in my sons info but I need to file my daughters.

When you use Online TurboTax, you get one return per fee.  Each return needs its own account and user ID.   If you use the same account and user ID for a second return, you overwrite the first one and lose it forever.

https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-online/00/25596

 When you use Desktop TurboTax, which you install from a CD or download to your own hard drive, you can prepare and e-file multiple returns for the cost of the software.  You can e-file up to 5 Federal returns—more if you mail the additional ones.  If you have multiple returns to prepare for family members, Desktop is more cost effective.

The TurboTax online editions can only be used for one tax return per account and User ID.  To start another tax return you would need to create a new account with a new User ID.   The same email address can be used for up to 5 online accounts - https://turbotax.intuit.com/personal-taxes/compare/online/