There were some good answers about preparing financially and legally by doing research, getting her will and and power of attorney in order, etc. But, to the question about preparing emotionally? Impossible to answer because it cannot be done!
You cannot. I am so sorry. But you cannot.
The day will sneak up on you and your emotional response will be unpredictable. You could be about to face unimaginable heartache. Maybe not. Maybe she will be one of those ladies that suffers in quiet dignity. Doubtful, but it could happen.
So here is my non-professional advice from somebody who is now where you may one day be.
- Don't spend all your health and mental energy in her foxhole. You can't save her. So don't consume yourself with articles and opinions on Alzheimer's and experts giving you false hope. Your whole life does not have to be about Alzheimer's. Some of it, sure. But you will lose all perspective and even communication skills if you never leave the foxhole.
- Expect otherwise perfectly normal friends, relatives, and siblings to experience rage over care decisions and seemingly insignificant things like whether she gets apple juice or cranberry or whether you play hymns in her room or jazz. They need somewhere to project their anger and helplessness. It might be in your direction. Get out of the way. Don't waste emotional energy on that. You do not have enough to spare.
- If you find that you are the one lashing out at people, stop. Talk to a counselor. You could potentially lose very close friends, damage relationships, or get fired from your job all because you're going through the stages of grief related to coping with your loved one's Alzheimer's.
- Do what you can to make her life as comfortable as possible. This will allow you to feel less helpless. There will be fewer and fewer things you can do as the disease progresses. So, read to her, sing to her, hang photos of family members where she can see them, chat about old family memories even if she has that thousand yard stare. Play music and keep her living area as chaos free as possible.
- Do not dwell on things that are imperfect: if her nursing home is not the most elegant, if they keeping losing her clothes, or if she lives in your home and you cannot provide her with best television set, so what? This upsets YOU, not her. Correct the things that you CAN and let go of the things you CANNOT.
- Eat. Sleep. Get fresh air. Exercise. Take care of you. You are useless to her if you fall apart.
- Read number 4 over and over.
- You need a hobby/distraction: book club, auto club, photography, painting, furniture restoration, bird watching, ANYTHING to take your mind some place fresh and engaging that has nothing to do with medication, diapers, purée food, and all the other things that will one day be your new normal.
A final (and my most important) word of advice comes from a line in the "Jurassic Park" movie where the character John Arnold is about to reboot the park's computer system to solve the failed fencing problem. As he flips the switch, Arnold quite simply says, "hold on to your butts". That is his warning that things are about to change in an unpredictable way.
Don't we wish curing Alzheimer's was as elementary as flipping a switch and rebooting the person's system? Alas, it is not.
So, hold on to your butts.