A used Pixel could be good like other people have said but the 8a should be coming out sometime this year and will probably be well within your price range. If you buy it directly, you can even install GrapheneOS on it if you want extra privacy!

The Samsung galaxy a54 could be a good fit.

Priced well, performs well, decent , and has 80% features (compared to a flagship ) of what 80% of people want in a phone.

I have a z fold 3, this may be anecdotal, but I've dropped it constantly and it still has no cracks on the screen. I was also able to remove most bloatware using adb.

Pixel 7 / pro (8 I think is too pricey, but that phone is my personal benchmark)

8th generation Pixels provide a minimum guarantee of 7 years of support from launch instead of the previous 5 year minimum guarantee. 8th generation Pixels also bring support for the incredibly powerful hardware memory tagging security feature as part of moving to new ARMv9 CPU cores. GrapheneOS uses hardware memory tagging by default to protect the base OS and known compatible user installed apps against exploitation, with the option to use it for all apps and opt-out on a case-by-case basis for the few incompatible with it.

https://grapheneos.org/faq#recommended-devices

It doesnt tick all the exterior things, but a Pixel 8 has very good security, GrapheneOS support (the only bloat free and secure Android you can get)

I am sure she can get a purple case lol, please dont use phones without cases, but okay please do I want to get a cheap used Pixel 8

I am very happy with OP12. It's not flashy or anything but it's clean, does the job, holds the battery well, does great photos. It's quite frankly really boring, but in a good way.
One feature that is a big wow for me is that it charges really fast. I plug it in at 5-10% and I have a fully charged phone after half an hour which holds for 2 days

Some answers for my xiaomi exerience with global ROM.

To change wallpaper or deafult ringtone you need to consent for data harvesting. I am using custom luncher no problem. There are couple of very annoing bugs: reboot messes the layout of quick actions. Sometimes open apps are missaligned. Battery optimization is so bad that sometimes my timer won't ring to remind me that my laundry is ready. I had overslept couple of times due to this. Xiaomi really pushes for their native video, gallery and app store but it doesn't prevent from changing the deafults.

I also got bad QA and audio DAC was broken for me.

I don't use assistant but it always pops up and wants my attention

G maps works good and links to google play open in google play.

Not sure if the screens are OLED but a lot of people sleep on Xperia phones and the flagships are pretty nice. I've used them for years and only switched to a Pixel 8 because it was on sale for $350 and included a year of unlimited service.

The only telephoto/periscope smartphones in the midrange tier at 6.7 inch display I know are from realme. Realme 12 pro(2x telephoto) and pro+(3x periscope).

It checks almost all your boxes easily from 1, 2, 3, 4(vegan leather), 5, 6. But, it doesn't have a purple color being limited to blue, beige, and red.

From my experience, Google mobile services all work fine with Xiaomi phones.

Bloatware you can disable with ADB.