Oh that's an interesting question and kinda tricky. Yes They have parents lol. Lets start with a positive. Lisa's mom passed away when she was younger but she still has her Dad and they have a really loving relationship. He’s very supportive of his daughter, so I think as long as Lisa is happy, he’d be happy for her.

Now Vicki and Krystal are another matter, they might both get disowned lol Vicki's mother Violet has always been really critical and harsh on Vicki's figure and already thought her daughter was too fat in her normal size. So when she finds out how fat Vicki has gotten I think she'd be both mortified and not surprised "Good lord, Vicki! I can’t believe this.”

“Good lord, Vicki! I can’t believe this.
Really now! I had hoped Europe might slim you down a little, not turn you into an obese cow.
Honestly… I’m not surprised. I always knew you’d end up fat. You always were.”
She tilts her head, looking Vicki up and down with a cruel smirk.
“Honestly… I’m surprised you’re not fatter.
Oh, how could you do this to your poor mother? Do you have any idea what people will say when they see you? What they’ll think of me?”
And if you think you’re coming home looking like that, you’ve got another thing coming, missy.

Vicki would not be going back home to that lol

Krystal’s parents are a little less defined in the story. She grew up in a huge empty mansion with parents who were rarely around. She was basically raised by the household maid and her nanny a big, warm, plump polar bear woman who was very kind to her. As an adult, Krystal’s parents are still mostly absent unless they want something from her. They care a lot about appearances and expectations, so if Krystal gained a lot of weight they might either disown her or simply pretend she doesn’t exist to avoid embarrassment.
Annabelle's family's I haven't figured out, I have sort of thought maybe she has a large family with lots of siblings but I don't know what they'd think.