She doesn't get better with age, sadly. In a few years, we'll see her run for her life from an accidentally drenched Elly because she's tasked with washing the house and forgets to check if all the windows are closed and deal with her asking Mommy if unintentionally bursting the bag of milk because she doesn't pay attention to that either means that she has to move. We also have to see Elly stand around screaming when she forgets where she put her glasses and so on and so forth. This means that the pattern is:
1) Lizzie is asked to do something.
2) Through inattention, she makes a mess of things.
3) Elly stands around screaming about how everything bad happens to her.
4) No one explains what Lizzie did wrong so she can do better next time.
5) No one teaches Lizzie to do things the right way.
6) Things are forgotten and Lizzie learns the wrong lesson.
7) Return to Step One.
This means that Lizzie's oblivious nature is a direct side-effect of her mother being an angry idiot who loves martyrdom and pissing away teachable moments because the stupid cow thinks that's asking too much of her. Eventually, she'll be perplexed that Liz goes to a stranger for advice instead of listening to her guano.