It is possible to have the same tickets showing in multiple
Disneyland app accounts. I suggest you have everyone who has a smartphone create an app account and have them add at least their own ticket and your youngest's ticket to their account. If you prefer, have them add all the tickets to each account. As long as your youngest will be with someone who has a phone, they can handle his/her tap-in for
Genie+.
This webpage describes how to add
UT tickets to a Disneyland app account:
https://www.undercovertourist.com/blog/disneyland-app/
FWIW, I'm one of the people who was told, back in January, that I could not get a paper ticket and had to use my phone or a magicband+ to tap into a Genie+ reservation. I was able to use a printout of my UT e-ticket to enter the park. I did not try to use that to tap into a Genie+ reservation. I used my phone. I paid attention when others were tapping in to Genie+. I never saw anyone use a paper ticket to do so.
It may be that you won't all need separate Disneyland app accounts if you can all tap into your husband's account. However, you should all have the Disneyland app loaded onto your separate phones.
(Edited to add last four sentences.)