I-485 Interview / new I-864 Co-Sponsor inquiry

[Joe & Bretts 0]

My wife and I got our interview date scheduled already, earlier than we were expecting but since filing covid assisted in my employer shutting down my location and was laid-off.  Have had a hard time finding work in my area that paid close to what I was getting and enough to meet USCIS requirements for my family of 5.  So my mother who is single makes enough on her retirement to meet the requirements for the 2 of them (her and my wife) and agreed to co-sponsor.  I am going drive down to Florida for to get her stuff and fill out another 864 with my mother, so do I just take this to the interview with us and give it to them to replace mine? And also is that correct that the sponsor only has to make enough for her (household of 1) and my wife and not my entire household?   Or will we be denied because i got laid-off and while can easily find work just not at near same high pay as before?  And even laid-off supporting 5 are not on welfare nor will be as I still get unemployment pay and my immigrant wife started working as well.  Thank you in advance.  Almost forgot - as for interview while she added to utilities they still only come in my name and only things in both our names mail is our bank accounts is that ok.  Even our credit card bill comes in my name as it did before I added her to it.