If my girlfriend didnt work last year how would she get her stimulus?

She does not qualify if she is claimed on someone else's tax return in 2020.   But if she was not and is otherwise eligible to receive the payments, she can e-file a tax return with no income and include the recovery rebate for the amounts she did not receive.   

Go to the search bar up top and type in stimulus (make sure you are all the way inside of your return or search does not function), hit enter, and then use the Jump to stimulus link to be taken to the questions.  She will enter 2 amounts.  It is important that you enter the amount you received for the first payment in the 1st box and the amount you received for the 2nd payment in the 2nd box.  Because the amounts paid out were different, if you transpose these 2 numbers, you may generate a recovery rebate that you are not qualified for or forego claiming one that you do qualify for.    Anytime you need to get back to that section, searching stimulus is the way to do it.   If she did not receive either, she will enter 0 in both fields.

Then go through the filing steps to e-file the return.