Print 4X6 photos from phone to Color Laser

[DoctorWizard]

So based on my recommendation, my grandma got a Brother MFC-3770CDW multi-function color laser printer. I have an HL-L8260 and love it, but I'm a computer geek and print from the computer. My grandma on the other hand, is not computer literate and an iPhone user. And at least 50% of what she prints is her photos. I cannot find / there does not seem to be a way - to print 4 X 6 photos from the Brother iPrint & Scan app, or any other method that I can find. The paper sizes are limited to A4, A5, Letter, and Legal. Nor can I find a way to tell it to print from the multi-purpose tray. LIkewise, same issue with the Android version.

Am I overlooking something? Is there a way to print 4X6 photos to the MP tray from a phone? That would be a REALLY BAD oversight if Brother did not include that ability.

(Yes, I know color laser printers are not ideal for photos. But she keeps complaining about ink costs and clogged cartridges, and she has had numerous different inkjet printers, all garbage. Plus inkjet photos fade badly in the sun, quickly. Not-so-much for laser prints.)

 

[Shadowman]

Have you checked for firmware updates or tried the Brother Creative Center?

 

[DoctorWizard]

Everything is up to date, and Creative Center is just a web site, intended for PCs where you can get templates for things like birthday cards. Trying to print photos from a PHONE.
(Well, I suppose you could use Creative Center on a phone, although at the very top of the page it recommends using a PC! And it's not for photos, and that still doesn't solve the paper size or tray issues!)