@grad_student_question
(A) the fact that you were in the USA a longtime ago does not affect your situation. You entered with your own F-1 in 2015. Thus you were exempt for five calendar years including the year of entry. So , absent any change of status or non-compliance with the visa conditions, you would have been a Non-Resident Alien till 12/31/2019
(B) your spouse came to the USA in 2019 with her own F-1 ( was she married to you before she came here or you got married here? ). Thus she would be an exempt person till 2023 end of year. How did she end up having a SSN, if this is her first time visit and on F-1. How did you end up with SSN ( because you were born here or because you lived her during better days ? ).
(C) why did you change your visa to F-2 ( a dependent visa ). AS long as she is NRA, you will continue to be NRA i.e. you do not have any independent status. But you also cannot work , do OPT or CPT --- you are not even supposed to be going to school.
(D) In any case, with your F-2 and her F-1 you are both NRA and must file form 1040-NR
