Mrs. Wilco is Rob's mother, who has not yet been given a name. She lives in an indeterminate place with her cat, Buttercup, and her dog, Chewie. Rob has visited her apartment on two separate occasions, once for Thanksgiving and once for Easter. The first time (during Thanksgiving) Rob had to fly there; but the second time he was able to drive, implying she might have moved. She has joined Rob in adopting a vegetarian diet, and has gone further to the point of forcing her cat Buttercup upon the diet, much to her dismay. She claims that everyone's a vegetarian if you stop giving them meat.
- Mrs. Wilco appears to be of Italian descent, as she has worn a sweater that says "Kiss me, I'm Italian!"
- It is unknown whether or not she is still married to Francis Wilco.