@blongtreylo - this is quite complicated for a message board and there are not enough facts laid out to straighten this out. I assume you are trying to amend the 2020 tax return (that is how to get the $600 - amending 2021 is a no go).
if you claimed your fiance and her daughter on your taxes, were they legitimately your dependents? if so, then why are you amending to get the missing stimulus money? it would have all reconciled on Line 30 of the 2020 tax return.
Please explain your 2020 tax return (we can get to 2021 later if necessary).
1) who did you claim as dependents on that tax return?
2) what is on Line 30 of Form 1040?
3) did you fiance and her daughter live with you for the ENTIRE YEAR of 2020?
4) did you pay more than 50% of the expenses of running the household in 2020?
5) did your fiance earn less than $4300 in 2020?
please be very specific in answering all 5 questions. THen I can help you with how to straighten this out.
