S10e

I would recommend a Samsung S24, its pretty well built and closest to an iphone as far ecosystems are concerned. There are better android phones, out there but I would start slow if shes never had android before.

Basically Xperia or bust if you don’t want to compromise on any of that. See the search results here: https://m.gsmarena.com/results.php3?nYearMin=2022&nWidthMax=71&nRamMin=4000&chk35mm=selected&s4Gs=0&s5Gs=0&idCardslot=1

If you are willing to compromise on size and get a bigger phone, your options open up a bit with low-end phones from various brands, like the Moto G line and Samsung Galaxy A line. For some insane reason, high-end phones lack the useful features of low-end phones like card slots and headphone jacks.

What exactly does she need the SD card for? If she just needs to transfer files to and from an SD card, an external reader (via USB) might be sufficient.

3.5mm jack can be substituted with an external adapter too and they’re not even half bad.

Both suboptimal of course but small phones that don’t suck are rare enough as is.

If size is the most important, get an a-variant Pixel.

See how the phone you’re considering scores on Don’t kill my app!

Best I can think of is Fairphone.
https://shop.fairphone.com/fairphone-5

But…
A) I don’t know if they deliver to, or even work in, the USA.
B) No 3.5mm jack, but I doubt you’ll find one tbh.

No modern phone meets those requirements. Sad, but true.

Phones tend to get bigger screens every generation. 3.5mm audio and sd cards are no longer a thing.

And if security is important you want a recent model that gets updates from the vendor (unles you know what you are doing with customs roms)

Look at Samungs or Google Pixel and see what size she could like. They all have good cameras.