This is because of an interesting habit she shares with most of her family: a rather poor memory of events. This tendency is why she could sit through a conversation in which Jim berated Phil for being a slacker because he himself had a wife, two kids and a real job at the age Phil was when he was being lectured and convince herself it never happened at all because of her need not to admit that Phil's life isn't really a bed of roses.
Similarly, she doesn't seem to make the connection between her own endless beefing about how hard it is to be a spouse and parent with Phil's extreme reluctance because she thinks of herself as being an active propagandist for how wonderful it is to be a wife and mother.
This need not to admit that the people she thinks are all laughing at her as she suffers imaginary cruelty after imaginary cruelty aren't doing so is why she glosses over every time she's either been oblivious to someone's feelings, forgotten that she's made family life look less enjoyable than a hitch in a Soviet gulag or been a vindictive, angry idiot pitching a fit because she thinks she's been insulted when she actually hasn't. Doctor Who might think that forgetting things is humanity's superpower but in Elly's case, all forgetting does is allow her to make the same stupid mistakes over and over again because she doesn't remember making them.