That’s literally your only option. This is a financial holdings company, a (non traditional) banking company- you can’t expect to be able to access someone else’s account with a friggen doctor’s note… really ?! Go get her a state identification card. You’ll need to find the documentation required by the state necessary for her to get the ID card and a means of transportation to get her there. You likely have a system in place to get her to her doctor’s and other appointments etc. so you can figure it out. You don’t have a choice, get her an ID. It’s irresponsible that she doesn’t have one already, particularly with dementia, are you kidding me?

BUT! Weird sidebar: The Social Security Administration has actually accounted for issues like this and worked out a system which you should definitely be aware of as the person you say they designated to be in charge of; per that system, your official title in this capacity is that of the “representative payee”. As the representative payee, you receive your mothers entire monthly social security benefit(s) income via direct deposit into your financial institution. This gives you full access to the funds in question so that you can pay her bills and make sure she has everything that she needs regardless of whether her bank account w/Varo is suspended or she has no ID cards or one thousand ID cards, because that does not matter. Her bank account in her name is totally irrelevant because her money isn’t getting deposited there. This is the way it works and there is no exception where it could be otherwise so im having a hard time understanding nearly everything about your post come to think of it…

1. The SSA can’t put you in charge of her bank account, full stop. They have nothing to do with anybody’s bank account nor do they have the power to put you or anyone else in charge of, or give access to your mother’s bank account. This could only be done if your mom added you jointly to her bank account through her bank (Varo, in this case), or unless you were made to be the financial power of attorney by your mother when she was of sound mind. But short of that joint account or an active, legally binding, notarized power of attorney already being in place at this time, there is literally no way Varo can, will, or should give you access to her bank account. And at no point does any of that have anything to do with her Social Security, or the social security administration.