Not receiving the help from family. Should I say anything or just leave it alone?

Do only what YOU want to do, regardless of what the rest of the family choose to do. Why expect to get blood from a stone? Your mother needs to spend her OWN money to hire caregivers in home to give you respite. Or get her placed in managed care so she can have more autonomy and you can have a fuller life w/o caregiving being the central focus of it. It's far nicer to be a visitor than a burned out and resentful caregiver to an elder 24/7. I can vouch for that as an only child who was in charge of my parents lives for over 10 years w no help from any family members. I had them in independent living, then Assisted Living, then memory care for mom during the last 3 yrs of her life. They were well cared for and I didn't lose my mind or my marriage and privacy in a misguided attempt to provide care I was unqualified to provide.

Wishing you the best of luck

Stop helping others financially. Use the money to hire someone to stay with mom (should be mom's expense) so you can get out.

You cannot control what others do, only your reaction to it. I would leave it alone, you can't make people do things they don't want to do. And you don't want anyone caring for mom that doesn't want to.

I read your profile and see that there is a lot of drug use and addiction in your family. On the one hand you say you cannot depend on your brother to help because of his addiciton problems. Here in your post, you say he's the only one you can depend on.
Which is it? There seems to be a serious communication problem going on.
Did you ever come out and ask your niece and great-niece in plain language why they will not give you a break and babysit your mother for a week-end?
Ask them and ask them plainly. Give them a chance to explain their reasons.
Does your mother have dementia?
Is she incontinent?
Does she wander around?
Is she aggressive and nasty to be around?
Did they always have a poor relationship with her?
Talk to them plainly and give them a chance to talk to you.
Also, you can put your mother into a nursing home or memory care facility paid for by Medicare and her secondary insurance for up to two-weeks a year respite stay. Yes, Medicare pays for facility respite caregiving services so caregivers can take a break.
Look into it.
A private caregiver can be hired to stay for the week-end too.
There are options so you can get some time off. Your niece and great-niece are not the only ones.

Makes no sense to me why you would do what you are doing, unless you thought they would help you with your mother and that is the real reason you moved there. Or perhaps care for you later in life?

Generally speaking, these type of plans do not work out.

The 24 yo is helping her mother, seems like some will be in school most of the day and if needed she can hire someone to help her otherwise.

All I can say is stop giving them money, use it for respite, place your mother there for a weekend or a week so you can have some time of your own.

In another post you say you are 59. Are you 59 or 69? If you are the fulltime caregiver for your mother, just how much help are you able to provide your niece and her family? Did she know there were strings attached to the money and help you gave them?

What is the plan as your mother needs more help? And what is the plan for YOU? Do you expect your niece and family to become your eventual caregivers?

What is your mother's financial situation? Are you POA? If so, then pay for respite so you can get away sometimes.

Please do not expect help from your family. Your mother should be placed into a permanent facility for yours and your family's peace.

Exhaust resources that might be available
Contact your local Senior Center see if they have programs that can provide caregivers or volunteers that can sit with mom for a few hours.
Area Agency on Aging.
Contact Alzheimer's Association and find out what is available in the area.
Use moms assets to pay for a caregiver.
Contact a Hospice and see if mom would qualify for Hospice. You would get all the supplies and equipment that you need as well as a Nurse that would come every week and a CNA that would come 2 times a week to give mom a bath and order supplies.
Other than your brother I would leave it alone, it is not your niece's responsibility to watch your mom.
Stop GIVING them money and "helping" them (whatever that means). If they need money they can work for it, they can sit with your mom for a few hours $15.00 to 20.00 per hour with a 5 hour minimum.

You say you moved there to help your niece who has five kids. If she needs help, how are they going to help you take care of your mom? Sounds like they have their hands full.

You don't mention your moms finances, but maybe she should be placed and then you can manage her care and visit her as often as you like. Then you don't have to rely on others to step up to give you a break. It's one of those airplane suggestions.... put your own mask on first before you try to help others.

Be gentle with yourself, and change your expectations of others.

What helped my mom was to move her away from the dysfunction. She is peaceful and not anxious. 2020 She chose a place for a AL respite (8 weeks) for me and my husband and liked it so much she looked at the other apartments in the same facility and determined that hers was the best. In 2022 she needed memory care because she would look for home sometimes and AL didn’t have locked doors. I have part time caregivers for her in the afternoon. What I have seen is family members have their mom or spouse in MC and they visit everyday. I call mom every day. Pro: having all of moms needs cared for lifted the load significantly and I could be her daughter and companion. Con: I made the mistake of expecting the facility to follow through on the personal care (showers, lotions, teeth brushing). Don’t pay their fees, hire your own person who reports to you. The facility people can be wonderful or indifferent. It broke my heart to see a person just going through the motions and not conversing with mom-her face showed it all, sadness of being a task. (I had cameras in her apartment and this happened multiple times with some of the staff). My caregivers were trained by me, they text me the end of the day letting me know how it went, they take pics of small movies of mom and mom has never looked better. I have them come in 1-5 or 12:30 to 5:30 to cover 2 meals. Mom likes to sleep so this works for her. When she moved to MC, the caregivers went with her. I was grateful I didn’t listen to the MC facility who said I didn’t need them. Staffing changes and new inexperienced people were hired and mom has the continuity of people who know and love her.