I should also tend to think that any interest in dogs Elly might have displayed as a child would have been stifled by playing on an exaggerated fear of disease and injury. It's like how one of my more delightful relatives convinced one of my more suggestible nieces that the merest exposure to ham would cause her to drop dead on the spot of a rampaging case of trichinosis. We might have convinced the poor sap that she isn't going to fall down dead but she still won't touch the stuff. Similarly, Elly might intellectually know that dogs aren't all trying to bite her and give her the rabies but any curiosity she might have had about them died pretty much the same time that Elvis told us not to step on his blue suede shoes.
The reason that I mention this is that Elly was prevailed upon to get a dog because another old lady with her head up her arse thought it would teach her responsibility. Given Marian's clear belief that only women who've been beaten down by tyrannical old men accept the four-legged symbol of patriarchal domination, it's probably the case that the old bat is less willing to respect Elly because, yes, she's taking orders from a mutt like a sucker instead of standing her ground and pretty much screaming at a windmill and declaring her intent to slay the obvious monster.