Sylvia Welker, portrayed by Betty White, is Victor's secret and common-law wife. From him, she had Roberta and they lived a comfortable life in Manitoba.
When she met Lois and her boys in Season 5's Victor's Other Family, she complimented that she looks like Victor and accepts her as part of her family. The visit was nice, but it turned sour when Ida Kenzel (having lost the case), showed up uninvited and unannounced. And apparently was violent with Sylvia in the past that in fact Sylvia had gotten a restraining order against Ida and it got to the point that whenever Ida showed up she would panic and run to hide in the den (although an armory probably would've been better) Sylvia even threatened Ida With a needle and the restraining order to get Ida to leave right before She demanded Victor's pension from Sylvia and the rest of her family because she claimed that she was his common-law wife. Lois chases a begrudging and vengeful Ida away in order for her to leave Sylvia and the rest of the family alone. Later on, it was soon revealed that Victor's pension is actually worth $30 Canadian and despite her best efforts, Ida insists on going through with the case because he was her husband.
When Lois revealed about the pension to Sylvia, she tried to deny it. Later on as the boys were bonding with their half-cousins, she returns again and it turned out that she wasn't related to Victor, she (and possibly Susan as well) was a product of Ida's affairs. However, Lois tells them that even though she's not biologically related to them, she still considers Victor, her real father. Sylvia finally agrees to hand over the pension to her as long as she never mentions how similar to Ida she is for hating Victor and holding a grudge ever again.