My niece is caring for my sister who is in the early stages of dementia. They have a volatile relationship. Should she be her caretaker?

I think that your sister should enter care so that her niece can have a life. Sympathy is well and good but it often keeps us walking the same tired circle like an old mill wheel pony. And to no avail with nothing changing. I would recommend therapy for the Niece. She has decisions to make about whether to throw her life onto the altar of caring for her Mother, or to have her own life.
I am so sorry, but I would tell her to recognize and embrace her own limitations, to comb through her options for her own and her Mom's life now. I sure wish her the best of luck.

As I wrote recently, it’s INCREDIBLE how many mothers are so MEAN to their sweet daughters.

They’re jealous of their youthful daughters.

I have no answers for you, OP.

I just want to comment on this:
“My nephews are not involved in my sisters care. I think they feel it is my niece’s job since she is her daughter/female.”

It has NOTHING, ZILCH, NADA, to do with that.

Your niece could have been a nephew. 5 boys. Do you think suddenly the other 4 jerks/boys would have started helping? Of course not. They would have listed the next excuse: the helping-sibling is soooo good at helping; we’re so incompetent, we can’t help even in a tiny way; etc.; whatever excuse.

The 4 boys/siblings are simply jerks. How do I now they’re jerks? Because in addition to not helping, they’re VERY AWARE that their poor-exploited-helping-sister is being ABUSED by the mother.

They also know, that if the mother would be in a facility, the caregiving/advocacy/solving problems, doesn’t end. The poor sister would, out of kindness, still help. Still get abused.

I don’t believe your niece is doing this to try to get love from her mother. She’s helping, because she feels it’s the right thing to do: a vulnerable, elderly adult who needs help. Unfortunately, it’s a vulnerable adult who’s abusive. You have the choice to stop helping, but then you have to live with that. It’s a very tricky, awful situation for your niece (and any abused adult child in this situation).

Yes, you should tell niece that she does not need to care for Mom. Your niece is looking for confirmation of love and she will never get it now. She does not need to take the abuse Mom gives. If Mom has money, a nice MC. If not, a nice NH. Yes, the female is the nuturer is still a thing. There are 4 sons and they too should be helping in some way. I know, dream on. But I have a DH who would never have abandoned his Mom. Would she have lived with me, no, but DH would have had her close by and visited her. And p, no, I would not have suffered for it.

Ah yes, the girl is subject to old age standards that no longer apply today, we have a life, we have careers.

If the brothers do not step up like now, the daughter should relinquish her burden, mom should be placed.

She should not give up her life for a woman who has no respect for her and is just using her.

Women like her mother are usually jealous of other woman hence the bad behavior. They also ty and sabotage the sibling's relationship, divide and conquer, remain the focal point of everyone's attention.

Time to break the cycle.

My suggestion would be that it's time for your nephews to step up. If they won't (and it's obvious they won't), then please help your niece disentangle herself from caregiving.

Please make sure she does NOT feel any guilt over putting her mother in a facility. Remind her that your sister favored her golden boy sons, if you have to.

I cannot answer whether your niece should or should not be her Mother's caregiver. That is for her to decide.

I suppose I would try to keep the communication open. To support her while she decides how to proceed.

My thinking is this;
Taking her Mother in does not have to be yes-forever or no-never extreme. It can be many things inbetween.

It can also change over time.

It could be live-in as a TRIAL. Then reassess. Add more home help as required eg sitter/social visitors, join a support group, get more info about her dx & how it progresses. Eventually personal care assistance & supervision is required around the clock. Many need to find a care home for 24/7 support.

Many many adult children feel they need to step in. Save the day. Fix.

Society pressure still exists towards the female, to be caring, nurturing, put others first etc. Be a 'good girl'.

I'd say your niece has done what many do. Reacted quickly in a crises. Stepped up to help. Fantastic.

What comes next is assessment & making longer term plans. Realistic plans. A plan suit ALL the people in the plan.

Read this to her if you like:

You are not required to set yourself on fire to keep others warm. (Even your own Mother).

Other solutions DO exist.

Keep us updated or chat if it helps.

You are doing the right things with the exception of taking your sister there which began this nightmare for your niece. Now help get your sister get the care she needs. Is sis in a different state? Does she have assets? Make a call to the Area Agency on Aging for information on resources available.