If you need the self-employment forms and are using TurboTax Online, then you need to use the Self-Employed version.
You can file your wife's return separately if she doesn't need the self-employment forms. But please be aware that pricing for TurboTax Online is not based on income, it is based on what you enter into your tax return. So even a low-income person might not be able to use Free. Please see this TurboTax FAQ for more information: Who can file for free using TurboTax?
For your son, if he is 25 or under and doesn't have a spouse/partner that is older, then he can use any version of TurboTax Online for free. You can read more about this offer here: https://turbotax.intuit.ca/tax/situations/young-filers-under-25
