Do I legally have any say in the final say on closing the business for good?

My parents have already appointed me as POA (I am only child). My father owns a small business which he is no longer able to care for. My mother runs the small business for my Dad, the thing is, she is really not physically up to it herself. My dad expects her to continue running the business no matter how sick she is herself. I have spoken to them both about this, but it does no good. They are not making a living at this business, it just seems to run my mom down. I reallllllly do not want to step in legally, but it is really hard to see my mom's health going down hill. Taking care of my dad is enough. My family moved close to them to help out. I cook, clean, run errands and drive them to appts from time to time. I take my mom out for a break when my Dad allows it. My husband does all the mowing, trimming, shoveling(in winter) and takes the trash off for them-amoung many other chores he does for them. Our daughter cleans my Mom and Dad's house and our son also helps mow and both of them run errands and spend the night with them at lease 3 - 4 nights per week to help out. I feel with all the sacarfies my family has made(my son had to change schools his Junior year in H.S.)-that my Dad should be willing to consider that not having to worry about both he and mom trying to run a business they are not able to run would be a blessing for me. I want no money from the sale of the business-I want them to have the extra money for whatever they want and rainy days ahead. I do NOT want to have to pull the POA card....but if I am left with no options, Thanks