If the real Jasmine were alive at the time the movie took place...
She would do a lot worse to Stan than what the lion did. Think about it:
Back in her day she tried to outrace her future husband (Hub). She tried to kill herself rather than be the newest addition to the Shiek's Harem. To top it off she was able to hold her own against assassins trained to kill Hub.
If she were alive at the time she would warm up to Walter much like Hub and Garth. To take it further also develop maternal instinct for the boy. If Stan ever harmed Walter like he did in front of her she would probably slice his face with the same dagger she planned to kill herself with.
Walter's mom was pregnant at the end of the film.
The way she told Walter "I haven't got a choice" when he demanded to know why she wanted to stay with Stan, despite him being an abusive jerkass to both Walter and his mom (the latter never shown but pretty heavily implied), it makes one wonder if she wasn't carrying Stan's baby at the time. Given the values of the time, it's possible she felt obligated to stay with Stan and possibly even marry him for the baby's sake. Which veers right into Fridge Horror
territory when you realize Walter's younger sibling is bound to go through the same crap he did... only without a pair of eccentric uncles to rescue him...
Jasmine the lion is Jasmine reincarnated
She's protective of Walter and immedately warms up to him, because he's like the child that Hub and Jasmine would have had, had she lived. Also Jasmine would have been "too restless for texas" because she was as adventurous as Hub.