No, it would just be too risky to have her mom get the stone. Doubtless she'd be willing to oblige, but if she started asking questions, accidentally made a wish while carrying it, or happened to be around when Jon made a wish, things could get problematic.
So, with no other options, Jon tried to figure out how to retrieve the stone herself. Getting out of the pool was simple enough; even as a human, that was done mostly with the upper body. She grabbed onto the sides of the pool ladder and lifted her torso out of the water, then slid her - oh, screw accuracy, it was easier to just call them tentacles - out of the water and onto the concrete pool patio.
That was the easy part. It was a lot trickier to figure out how to move around with these things. The main problem was that, although they were fairly muscular, they completely lacked any skeletal structure. On the one hand, this meant they were about as flexible as they could possibly be (it would additionally have granted her the ability to squeeze through extremely tight spaces, if it hadn't been for that pesky human torso having so many bones.) But on the other, it meant that any attempt to lift herself into a walking position was just muscle pushing against muscle. A skeleton might limit flexibility, but it provided structure, which was something you needed in order to move outside the buoyant, free-floating environment the water provided.
Of course, there wasn't a lot she could do about that now. After multiple tries, several falls, and a couple minor bruises, Jon settled on holding herself a few inches off the ground, which gave her a little room to work with (and kept her from "scraping the undercarriage," so to speak,) and extending one group of four tentacles out while bunching the other up against her waist, using the two "proper tentacles" to steady herself. This resulted in a rocking motion that was pretty much the definition of "ungainly," but it worked, pulling her forward at a clip that, while far slower than she wanted, was at least manageable.
In a little while, she had made her way across the yard and to the back door. As embarassingly silly as it seemed, she went ahead and used one of her proper tentacles to open the door; it was easier than getting her torso within arm's reach. She slipped inside and gently shut the door behind her, hoping not to draw attention. Luck was running with her, for the moment; she could hear her mom having an involved phone conversation out in the living room, probably with aunt Jackie. Jon crept carefully and quietly down the hall and up the stairs.
Climbing a staircase was even slower going, but she eventually made it up. She was surprised she wasn't friction-burned to hell by now, but it seemed that her squid-skin was tougher than it looked. Making her way down the hall, she caught a brief sideways glimpse of herself in the bathroom mirror and paused for a moment. Earlier, she wouldn't have thought twice, but with the end of her femininity safely in sight, Jon was feeling a bit more curious. She turned to investigate, slipping into the bathroom and raising herself high enough to get a good look.
The girl in the mirror was beatiful. Jet-black hair that was curly enough to form little ringlets without looking bushy, skin pale enough to look delicate without looking sickly, a pretty, feminine face, a gently curved body, and...well, not to put too fine a point on it, but she was stacked. Jon had never quite understood how bra sizes worked, but she guessed her breasts were about the same size as Karyn's wish-enhanced mammaries, maybe a little smaller. All in all, quite an attractive young woman. Except for the squid parts, which were currently doing a commendable imitation of the floral wallpaper in the hallway behind her, this was totally the kind of girl Jon would do. If the girl wasn't him, that was.
And on that note, it was time to take care of this. The stone was in her room, down at the end of the hall, on her nightstand. All it would take was one wish to get her life back to normal, and then she and Karyn could work on fixing everyone else's. She was eager to have this over with.