How do I get my sister to help for more then 4 days a year?

Peties, in my experience, when family emergencies occur, an adult child often swoops in to to manage the crisis.

Once the crisis phase is over, there's time to reassess, and to take EVERYONE'S needs and resources into account.

Do you want to live with dad? Do you want to in in FL, away from your kids and grandkids?

If not, start with getting a professional needs assessment for determine what dad's care needs are.

Assess his finances--income, assets and entitlements.

Figure out a plan that works for you both. Your life matters as much as dad's.

You are “living with my dad because he needs the help”. Your dad needs help. That doesn’t mean you have to be living with him. Separate the two things.

Your sister isn’t thinking there is a problem because you solved the problem by moving in with Dad . She’s not going to help enough .

Get Dad placed in a facility either in Florida or near where you live and move back home. Your father’s needs will only increase and you will not be able to help him alone. You say he can’t live alone, I’m assuming he would need an aide 24/7. Most folks can’t pay an aide 24/7 for in home care , it’s too much money . If Dad owns his home sell it and use that money and any other that he has for a facility . Don’t use your own money . If you have to , sell the vacation home as well . I hope someone has POA .

Your home is not in Florida .

The better question here is why in the world would you give up your family and life to move in with your dad? I mean really....don't you think that it's you that has your priorities mixed up and not your sister?
Your sister has it right. She's putting her immediate family before anyone else and that is how it should be. You could learn a thing or two from her.
If your dad can no longer live by himself then do him(and yourself)a favor and have him placed in an assisted living facility where he will be around folks his own age to enjoy and have fun with and also receive the care that he needs, and you can get back to making your immediate family a priority. Because remember you can never get these days and years back that you're losing with your children and grandchild.
Hands on caregiving only works when it's working for all parties involved and it's obviously no longer working for you, so start today with looking into the best facility for your dad.

You can't expect your sister to fulfill the choices you made. She is entitled to go on vacation just as you are. Why would you hold that against her? If dad can no longer live on his own, then choices have to be made by him to rectify that situation. But you don't get to make choices for your sister.

They don't want to be more involved. As you've discovered, caregiving is difficult and most people don't want to do it.

It's natural for you to feel resentful. Why would you try not to? You gave up your life, and being with your children and grandchildren, all because your dad can no longer live alone. Apparently he had no plans for his elder care other than you and your sister. That's on him.

You need to tell dad you can't do it anymore. That you need to be with your family. Then explore other options, such as assisted living or a nursing home for him. You've done your bit, and you matter as much as he does. So go.

If dad and sister have a fit over this, let them figure it out together.

Just read your profile. Your dad is in his 80’s with Parkinson’s disease.

I don’t know what stage of Parkinson’s disease your dad is in. The latter stages of Parkinson’s are quite challenging.

Are you planning on living with your dad for the long haul? Have you considered placement in a facility to allow your dad to receive around the clock care by a professional staff?

I fully acknowledge that being a caregiver is too much for one person to handle. I understand how hard this is for you.

I was my mother’s caregiver. She had Parkinson’s disease. She died at age 95.

Your sister deserves to make her own choices in life, just as you do.

I hope that you will consider resuming your life with your family. Go back to being your father’s daughter again instead of his primary caregiver.

You won’t be abandoning your dad if he is placed in a facility. You can be your his advocate and oversee his care. Wishing you and your father well.

Feeling resentful is ok.
Asking questions is good.

"Left my family and moved".
Why?
"living with my dad because he needs the help"
Why?
"he can no longer live alone.."
Why not?

Does Dad need help through a short recovery? Or longterm?

A significant sudden health event? Or maybe a slow progression of disease or decline?

How has he adapted to his new situation? What changes has he made? Has he hired home help? Plans to downsize, move? What's his plan?

Your sister is not going to do anything she does not want to do. She would already have done more. Forget about pressuring her. It won’t work.

Get some outside help in place or consider how to place him in AL.

To be fair, no one else is responsible for what you chose to do. I can’t believe you left your family. Are you married?