Being Screwed By A Company I No Longer Own!

Back in 2021 my step brother convinced me to go 50/50 with him on a general remodeling company. Everything went great for the first year and we received and completed a lot of work. My brother had told me he had received a builders license, and all was supposed to be good. We did in 2022 however have a customer who wanted a 3 season porch configured, and extended out an additional 10’. We did other miscellaneous interior work as well “bathrooms and kitchen” but the installers he hired for those were sub par to say the least. The plumber he sought out didn’t pull permits nor did he. This is when I found out he had failed his license test previous, and he couldn’t pull the permits for the porch conversion nor the addition to it. The customer requested a refund on this portion and I had told him to refund her. Work carried on but I started to not have a say in the business so about a year ago we drafted up, signed, and notarized a legal page stating I no longer had any shares or part in the company including all future problems that may arise. Well shortly after that is when the lawyers started coming. As stated earlier money was supposed to be returned, and wasn’t, so now she is suing the company and me directly for that as well as sub par work. There is also another person trying to sue him now. What legal obligation do I have for lawsuits for a company I no longer own nor work for?