yes i agree 64gb is fine for most cases, but shooting 4k 60hz w/ super hdr. its gonna eat up memory very fast.Really depends on the kind of usage. My mom will be fine with her 64 GB iPhone 8 for years to come.
64 GB IMHO is the perfect size currently for the entry level storage tier, so I'm really glad they made it that across the line. Didn't expect the iPhone 8 to both stay at 64 GB base and still go as low as 449 $.
if your mom's iphone 8 shoots the the res and frame as the 11. she will no doubt needing more space.
again 4k 60hz super hdr doubles the memory size by 2x.