Re: back Again!
Deb is right. It is the dementia that is getting worse so she forgot to take her med. She probably doesn't know what they are for so the pills are here and there.
In terms of memory loss, the pills won't make any difference. She forgets more because it is the disease that gets worse/progressive. Well if she needs some heart medications and doesn't take them, it may be bad for her heart. So it is important that someone is there to give her the pills. Don't expect her to remember even the med. box! She may be confused by the timing as well.
For now, you may want to consider hiring part-time caregivers in the day while your sister is not there to make sure she is fine. Alzheimer's or dementia requires different levels of care throughout the journey. She may need 24/7 care now so you need to find people who can take turn to do it. Try home care before you consider AL or even memory unit. It is slowly getting worse. There are many levels of care. When we cared for my late FIL, it went from part-time home care to 24/7 home care and to the memory unit.
It depends on her need.
Right now, she needs someone there when she needs medications.