Prosport/Monterey/Nauti setup questions

Dd2is 5.8 and rides in a Nauti in my Kia Sedona that has curtain airbags and in a True Fit in Dh 2004 Corolla. Equally throughout the school week but exclusively in the van on weekends and family outings. I recently looked up the ratings for the Corolla and the side impact crash rating is poor. I wanted to give her a seat with more SIP.
My thoughts are get a Prosport for Dh's Corolla or move the Nauti to Dh car and our extra Monterey to my van. She originally rode In a radian center until dd3 complained about the True Fit Rf and we switched their seats. Dh can't get a good install center with seatbelt with the True fit in the corolla plus Dd1(10.5 in a seatbelt seems squished) . Her stats are 5.8 yrs-44 inches tall-44 pounds-16 inch torso. I'm a little frustrated with not being able to tether the Prosport after 52 pounds and the 50 inch height limit but I don't know if we will need that much harnessing time? Wwyd?

Question 2- Dd1 is 10.5 in a lbb in my van. Dh says that her head is too close to the roof and our van has good crash rating for everything but roof strength which is poor. She sits up higher than dh and I. He wants to take her out of the booster but the the shoulder belt is high on her neck. Another Wwyd


Thanks! I hope this is the right place to post- if not-feel free to move

Anybody

I also have a Sedona and I would try your dd1 in the 3rd row passenger side outboard. My dd1 passes the 5step test there easily (but I still have her in a backless booster).
For dd1, can you sell the TF and get another GN?

It is late, so maybe that's why, but I'm kind of confused about what you're asking.

Is this it? dd1 (10.5) rides without anything in the small car and in a lbb in the van; you don't like her head being close to the van roof. I agree with firemom here.

dd2 (5.8) rides in a nautilus (van) and truefit (car); truefit can't go in the center so you want more SIP for the car. If you are comfortable with the SIP of the nautilus, that seems like the easiest fix; move that to the car and she gets a Monterey for the van (assuming that she will sit properly and it fits her etc). The other option of buying a ProSport should work as well; I wouldn't be concerned about the top tether weight limit as your dd should be well ready to move to the booster function of the seat by that weight. Same thing for the 50" height limit.

dd3 rides in a RF radian and is fine.

Did I miss anything?

Sorry! I forgot to add that I need to fit 3 in the Corolla occasionally. I just got another nautilus on sale at target and put it the corolla. The Monterey didn't work for dd2 just yet. I put dd1 outboard 3rd row In the Sedona and she fits the belt.
She'll be outboard in the Corolla and center if Dd3 needs to ride bc I can't fit her onside air next to the Nauti. Think that's it! Sorry so jumbled but I think we figured it out. Thanks!