How do I get people to understand what is going on with my mom?

I have 5 statements at this time. I have a lawyer to get gardinships, or at least power of attorney. I have ste up different doctor appointments for her. On of which is a physiological. I think I spelled that wrong. Sorry. But her friend keeps telling her not to talk to certain doctors. I don't know how else to get her evaluated. An I wasn't going to keep the pepsi from her. I just meant that everything the friend is telling her is not for the good. Now she keeps telling me she doesn't want to go to any doctor she has to talk to. Well you have to talk to every doctor you go to anyway. It doesn't make since.

OK, I'm going to skip past the family dynamics and go straight to the question. Even if she has early dementia she has free will to do whatever she wants. To use your example, if she wants to gulp pepsi from morning to night, and her friends want to bring it to her, there is little you can do about it. Forbidding it, hiding it, pouring it out, telling off the friends all just make you sound like a shrew and lead to anger, confrontation and accusations from everyone. You can refuse to buy it, you can refuse to bring it to her, you certainly can refuse to be responsible for her dental repairs, but you can't stop the behaviour. If you stop trying to be her parent she may stop acting like an out of control teen.

As for no one else seeing a problem, that is common. You are the one with her the most so you pick up on all the subtle changes. And the rest of the family is content to not rock the boat, if they have let you sacrifice your life for 23 years they are hardly about to step up now, she has become your lifelong burden simply because you are the one who chose to carry her.
Work to get all the legal documents in order that you will need to care for her. Make sure she has healthcare and financial POAs, has talked about advanced directives, signed hippa forms so you can liaise with her doctor and has a Will. If you find you need extra help don't waste time hoping for volunteers, plan how you will pay for outside help.

Wow, ok. I believe I do need help to a degree. My mom first married at the age of 15. An has never been on her own. When my dad died in 68 she remarried about 1 to 2 months later. But their was always someone their. Yes she knew how to pay bills. But when my step dad passed in 2004. Right before that he asked me to move back home and care for her. She then handed over all the bills and responsibilities to me. I have to daughters I have put through college on my own the oldest live on her own now and the youngest is at the end of her JR year in college. She has been dependant as you put it her whole life. My sister also lives with us. Her friends have also seen her memory problems. But when it comes to getting her help they say shes fine. An no we don't have what you would call the perfect family.

I suggest you get some therapy for yourself to figure out why you are involved in this co dependent relationship with your mom. At 53 she may have needed some support when she lost her husband, but she hardly needed a permanent live in caregiver. Why has she become so dependent on you, and why did you let her?
You mention a daughter, how old is she? Where is her dad? Either your daughter predates the time you moved in with mom, making her old enough to deal with grandma herself, or she has grown up in a very dysfunctional household.