Unable for my partner to sign in to our shared Apple account …

My partner is unable to sign into the shared Apple iCloud account we share. Her password — as verified by 1Password — does not verify, so their iCloud account is unreliable. They are unable to update their Apple Watch system software. They are unable to get Apple Pay satisfactory paying. Mail seems more frequently than it should to be cocking up, particularly with mail servers. Does anyone see a common interconnection? Does anyone have any thoughts on any of these tangled threads?
Can I help them create a new password?
Might that creation of a new password somehow confuse and disrupt my password and my interaction with my portion of my account?
I’ve only been using Macs since 1986 … but perhaps that long experience is part of my problem … There are too many time when I think or know that I’m losing some of my faculties …

I am confused by the “iCloud account we share” and “Her password”. iCloud accounts, best that I know, are very individual things. The account my wife and I share we must use the same Apple Account (new term for Apple ID) with the same password. We have our own Apple Accounts and passwords in addition to the two shared Apple Accounts (long story why so many accounts). If you are indeed sharing one Apple Account on iCloud, then individual stuff like watch updating may be get convoluted.

Interesting, Earl! That goes some way towards clarifying our situation. My partner’s solution was to create a new password for her iCloud account. After that, things have so far worked.
Thanks!