If you are using TurboTax Online, each return would be separate, so you could choose Premier for yourself, and Free (or another version) for your children.
You can do all the returns in one account, but be aware that returns and information can’t be transferred between accounts. So if in the future, your children would like to do their own taxes, you would have to let them use your account. Or they would have to create new accounts, without access to their previous returns. It may be best to make an account for each of you, then you can hand over the accounts to your children when the need arises.
If you are still need more information, you can contact our phone support using the form on this FAQ: https://turbotax.community.intuit.ca/community/product-information/help/how-do-i-contact-turbotax-fo...
