My 19-year old daughter is a full-time college student living at home with parents and working part-time jobs. Can she file jointly with us?

[xmasbaby0]

No.  Only legally married couples file a joint return.  You do not add your daughter's income to your own tax return.

MY DEPENDENT HAD A JOB

If your dependent has a W-2 for his after-school job, summer job, etc. you do not include the information on your own return. You can still claim your child as a dependent on your own return.  He/she can file his own return for a refund of some of his withheld wages (he won’t get back anything for Social Security or Medicare), but MUST indicate on it that he can be claimed as a dependent on someone else’s return.  (Supervise this closely or prepare it for him!)

If your dependent’s earnings were over $400 and were reported on a 1099Misc or 1099NEC then he must file a return and pay self-employment tax for Social Security and Medicare.

You might also want to use free software from the IRS Free File versions:

https://apps.irs.gov/app/freeFile/

[VolvoGirl]

Not exactly.  You can claim her as a dependent.  She might have to file her own return for her income.  She will have to set up a separate Online account.  

Be sure on their return they check the box that says they can be claimed on someone else’s return.  If their only income is W2 and under 13,850 they do not have to file a return except to get back any withholding taken out.

Filing requirements for a dependent

https://ttlc.intuit.com/community/children-dependents/help/do-i-need-to-file-my-own-taxes-if-i-m-a-d...