@serados Was there 3 people listed on your 2020 tax return ? You , your spouse and a dependent ? If so you should have gotten 4200 (1400 x 3) so 2100 is your half of the total. So are you sure you did not get the full 4200 advance stimulus? Just because your wife didn't get the 6475 letter doesn't mean you don't need to enter in the total amount you got between you both. Did you check the IRS online system for both of you yet ?
Enter what you want but if the IRS doesn't agree with what you said then they will make the correction on the return automatically however this can delay your refund for some time.
If the IRS said they sent the advance and you did not get it then you have to put a trace on the missing payment. https://www.irs.gov/coronavirus/third-economic-impact-payment
