Do keep in mind that dementia can conjure all sorts of stories. For a while my mother insisted she had two husbands. She also became very angry that our pool water was cool (broken heater) which made her daily lengths uncomfortable. She cannot swim and has always loathed getting wet. (fearing for her safety we immediately closed the pool) She is a retired elementary school teacher but for a few years she insisted she was a neuropsychiatrist. (she’s a teacher again, sometimes retired, sometimes on her way to work) She swears she has never ever seen my house in spite of having lived here for almost 20 years.
To ask Fawnby's question a different way, does it matter to your mother? If she brings it up, why? Is she rejecting her? Besides the 'hanging around with us' comment, what about the rest of M's story?
Another slant, does it matter to you? And to your sister? What does your sister say about it? If she was old enough to 'hang around with you', she should have some memories. It seems like your sister is the one who could be deeply distressed by this.
The best way for you to find out if your sister is truly your sister or your mother’s daughter is for you to purchase DNA test kits from ancestry.com or 23andMe.com and do the DNA test and you will get a definitive answer. You will need to purchase three DNA test kits — one for your mother, one for your sister, and one for you. Then all three of you will follow the instructions and then send the kits back. This is a simple test where you just follow the instructions by spitting into the tube, seal it, and send it back and within two weeks you will get the result. The results will be online for you to see. BTW, when you do the DNA test, be prepared to find out about other relatives that you never knew existed.
Hoping you will do the above which will put your mind at ease once you get the results. Just know that DNA never lies, so prepare yourself for whatever results come your way.
Since you put your post under the Alzheimer's and dementia category, I'll assume your mother suffers from dementia. She may be confabulating, or confused, or may be telling the truth, who knows? Have you ever seen your sisters birth certificate? If your mom adopted her, she'd have a very different looking birth certificate than yours. Does she look like other family members? You can do a DNA test or Ancestry.com if you're wondering.
I'd probably chalk this statement off to confabulating, because by now, the truth of this situation would've come to light, I'd think. These elders often hear something on tv and then get thinking it's THEIR life and that's how confabulation is born.
Do keep in mind that dementia can conjure all sorts of stories. For a while my mother insisted she had two husbands. She also became very angry that our pool water was cool (broken heater) which made her daily lengths uncomfortable. She cannot swim and has always loathed getting wet. (fearing for her safety we immediately closed the pool) She is a retired elementary school teacher but for a few years she insisted she was a neuropsychiatrist. (she’s a teacher again, sometimes retired, sometimes on her way to work) She swears she has never ever seen my house in spite of having lived here for almost 20 years.
Another slant, does it matter to you? And to your sister? What does your sister say about it? If she was old enough to 'hang around with you', she should have some memories. It seems like your sister is the one who could be deeply distressed by this.
Do you have any idea what M is talking about?
Hoping you will do the above which will put your mind at ease once you get the results. Just know that DNA never lies, so prepare yourself for whatever results come your way.
I'd probably chalk this statement off to confabulating, because by now, the truth of this situation would've come to light, I'd think. These elders often hear something on tv and then get thinking it's THEIR life and that's how confabulation is born.