I have a friend with early onset Alzheimer's disease and her family has done very little to help. How can I assist her?

I don't really see how you can help other than what you have done. I might consider family that you believe she isn't taking her medications consistently, and whatever other information you DO have that is worrying to you. Tell them that you believe she is currently unsafe in her own care (if this is so) and that at the risk of seeming like a meddling friend/neighbor, you are considering reporting her to APS for a wellness check.
In home care is extraordinarily costly. You cannot really get someone to administer drugs and that's it. It is usually a minimum of 30.00 an hour 4 hours a day three days a week minimum. And that leaves all other hours uncovered.
If you get no response do report to APS and let them handle this.
I agree from what you have said that she is likely in need of at the least assisted living without a support system in her area, and I would caution that you cannot take that on.
Family will, of course, need POA and MD letters of incompetency to do place an elder in LTC whatever type it is.

Who are they, her family? IMO once someone has been diagnosed with a Denentia its time to place them according to how bad it is and how much money they have. Early onset usually means the person is under 70. From what has been said on this forum, a person with Early onset declines faster than some who contracts a Dementia later on. People can have an episode overnight. One day they are doing OK with some supervision the next day not be able to be alone.

Is the doctor aware she is alone and son not coming for a few weeks? Hopefully this doctor is a Neurologist. A PCP should not be dealing with a person suffering from ALZ. If doctor does not know the situation, he should and maybe should call the son.

Its nice you are such a good friend but legally there is nothing you can do for this woman. Her son needs to realize how important this is now.

Hi topemtb, you are an awesome friend. The first thing to assess is whether she can really wait for the family member to come, or if it's more urgent...in which case you may need to call 911 or APS.

Situations like this can have many variables that direct what should be done. You don't give much other inform that would be helpful, like how old she is, what state she lives in, what her medication is for, and whether or not she knows if she has an assigned PoA.

If you are laying eyes on her situation in her home, like she is disheveled, her home is more than just messy and dirty, or she has neglected pets, unopened mail, food rotting in her fridge or sitting out, dirty dishes laying about... these would be concerning clues that she has memory impairment, confusion, disorientation. This could be from things like a UTI, dehydration, vitamin deficiency, improper dosing of medication, diabetes, high blood pressure, stroke, to name a few. If you are able to get her willingly to her doctor sooner rather than later, it would be a good start to rule in or out any of these causes (but you need to be told what the results are if she's not able to remember them so make sure to have her write in your name on the HIPAA form for Medical Representative that you should request at that appointment). If none of these are the cause, then she needs a cognitive and memory test.

If you are only getting information from her (like she's the one telling you they "just want to put [her] in memory care") this may or may not be true. You need to know that if she is in a confused state she may sincerely believe what she's telling you is accurate and real. And often with early dementia, there's just enough truth and fact in a story that makes it seem believable.

I guess you could be the one to make sure she's getting her meds consistently and correctly and definitely go by what is written on the prescription bottle, not what she tells you. FYI the doctor is not the one to intervene when s/he "did nothing further knowing her condition" -- APS is who you need to call and report her as a vulnerable adult. They have the legal authority to act. You can diplomatically inform the relative that calling authorities may not be able to wait, and see if they get the clue. I wish you all the best and a good outcome for your friend. Bless you for standing in the gap for her!