Adding fingerprint too difficult for some users

My mum needed a new cellular telephone (phone) so we got FP6, which I was going to use and give her FP5. It’s rather disappointing. It’s smaller, though I am a critic of always increasing them to size of phone tablets (phablets) people usually don’t like newer to be smaller than what they already have… so there should be a large and medium or small model. I dislike the switch on the side being where I’m used to volume buttons, so I won’t even use FP6. I thought’d it confuse mum, but she said keep it instead of paying restocking fee… and it did confuse her: she now doesn’t know how to complete adding fingerprint because the switch is visible but power-button/fingerprint-reader isn’t (despite is where it was on her older telephone). By maybe late 2010s when you add fingerprints, decent telephone PCs show you the progress of how much your fingerprint you added, and what parts or left. FP apparently doesn’t at all, so this seems impossible for her. She has a hard time understanding you have to move to scan the sides and top of your finger, because the process doesn’t show what’s done and left: the image is 100% useless. Can FP please upgrade this software to show what’s done and left while adding fingerprint? Even adding her face is hard at this point. Maybe she can do that after a rest, but unlikely fingerprint (it was hard enough for her on telephone PCs that do show what’s added and left).

Is it an option to use a pincode instead of the fingerprint?
Then your mum only need to press the button to start the phone and then type a pin code.
Or besides a pin code it’s also possible to use swipe, a pattern, a password or nothing.
See the app Settings
Security an privacy
Device unlock
Screen lock

And remove then the fingerprints and undo the option Unlock your phone Using fingerprint.

We use fingerprint and face in addition. PIN is time-consuming and can be forgotten; probably similar with login patterns. I guess she had Samsung before (which has gone bad) and it might take a lot of extra work to make the fingerprint setup screen as good.