Mother Gargle is always so upset with Brutus over the general "mother hates her son-in-law" trope that I'm pretty sure Ol' Ramona hates Wilberforce as well. In their (very few) collaborations together, Ramona doesn't seem all that fond of him. Basically just going through the motions of being a grandparent. Maybe it's because he's 9-years-old and it's scientifically proven that all kids stop being cute at 8.