Fabric Softener Question

meltoine

Since I'm staying with my mom when I go back to the US to deliver LO, I will be using her W/D to prep my dipes and clean them after LO arrives. I know she normally uses liquid fabric softener in every load. Do I need to worry about residue in the washer affecting the dipes? Should I clean out the washer (vinegar?) before prepping them? Or is this NBD?