I filed jointly that's means her social is still on my return
The checks should be sent by individual name and not jointly. However, that is an assumption. So you will have to wait and see what happens. The IRS will send you a notice in the mail within 15 days after you should have received the funds with information on what to do if you did not receive the funds.
So I just filed a month ago for social security do have any idea how that works
When you applied for Social Security benefits did you also provide a bank account routing and account number for the direct deposit of the monthly benefit payment? If you did you May be receiving the stimulus in that account. However, since you just applied the IRS may not have that account information available to them from the Social Security Administration.