OK, I'm getting it.
You're the spouse, so decisions over your wife belong to you if she's incapable of making those decisions. Your daughter obviously believes that you're not up to the task, so because she's executor of your estate(s), she's treating this as if she has Power of Attorney. I'm assuming that, please tell me if I'm wrong.
If I'm right, you need to see an estate lawyer. Get your wills amended if you wish for your daughter to have no authority over your estate. She can still be a beneficiary if you like, but if you don't trust her to respect your testamentary wishes then someone else should be the executor. By the way, "executor" isn't a term used any more, it's called "estate administrator" in most circles. But old lingo dies hard.
I'm sorry that your wife has symptoms of dementia, that's hard on both of you. Talk to her doctor, get an opinion on her capacity. If she still has periods of lucidity then she should sign a Power of Attorney over to you. You already have that by implication as her spouse, but if she does that document then it's an acknowledgement that she needs help with her personal care and finances because of her condition, and she's specifically named you rather than your daughter. An estate lawyer can take care of both of these issues for you. It shouldn't cost much.
Does that make sense? Please reply with your questions or comment. If I've answered you I'd appreciate a positive service rating, please.