2020 or 2021 (can’t remember) Black Pearl 97 @ 153 (short). She’d probably go for a 156ish.
You can look
here to compare a few of these skis (BP97 is from 2022 however).
Sidecut radius are similar.
Weight are different. Both Total Joy and Wild Belle are lighter, but by different amounts.
Running length are longer in the Wild Belle and the Total Joy due to less rocker. Typically, for piste skis I would go shorter than my powder skis to have a more comparable running length (length of the ski touching the snow when flat on the ground). With that in mind, I would probably go 150/153.
The Total Joy 153 is the same average stiffness as the BP97 153. All the other skis are stiffer in bending by about 20-25%. Stiffer will make a ski come alive at higher speed, give you a higher speed limit (when the ski starts flapping around) and will transmit more of the terrain to your foot/shin. Softer skis are easier to initiate turns and will smooth the terrain by conforming to it. They won't push you out of moguls as much either.
These skis are also softer in torsion. It is a bit hard to directly compare with the BP97 because the width play a role in the amount of torsional stiffness you should have. However, all these skis are at or slightly below average for their size/length in their torsional stiffness, which mean they should be great for intermediate skier. The Total Joy 153 is the softest. A torsionaly stiff ski will require accurate leg motion to engage and release but will track very well and have a lot of edge grip. A torsionnaly soft ski will be more playful.
Many Head skis, including the Total Joy, have very flat stiffness distribution (i.e., stiff tip/tail but soft center). That is pretty unique across all brands. Maybe some people can chip in about that feel on-snow, or maybe you can find some reviews about them...
Note that stiffness and dimension change with the specific length you choose.