I don't want my mom to take my grandma into her home when we leave as caregivers. What other options are there?

The options that are available depend on several factors. The first would be your grandmother's finances, the second her level of impairment and care needs, and the third her geographical location. It would be easier to discuss the options if we knew more. For example, you can hire in-home care or even just a companion if your grandma is fairly self-sufficient, but that type of care is expensive if she's paying out of pocket. Some states/counties have free or sliding scale home help for seniors, but it all depends on what's available in the location where your grandmother lives. In my state, such help is available only if the senior qualifies for Medicaid long term care services, which involves both a medical and a financial assessment. There's assisted living and group home care (also called adult foster care), but these are also expensive and may or may not be covered by insurance or Medicaid.

There are lots of factors to be considered, but I agree with your initial reaction. For your mother to take your grandmother into her home should be a last resort. The arrangement will become increasingly stressful and difficult for your mother while your grandmother will become increasingly comfortable with the arrangement and dependent on keeping the status quo. It will be much easier to arrange care outside your mother's home now than to move your grandmother out of your mother's home a year or two from now when your grandmother has become settled there. Please investigate all the options and engage a geriatric care manager or consultant if needed. It could be well worth the small initial cost.

Is adult daycare a possibility for your grandmother?

A nursing home is one option. However when someone goes into a nursing home the caregiving doesn't really end, it just changes. Having a loved one in a nursing home can be very time consuming and stressful.

In-home care is another option. If your mom brings your grandma into her home your mom can hire caregivers to supplement her caregiving duties. She can have a caregiver just to do bathing and grooming (several times a week) all the way up to full-time depending on your grandma's needs and your mom's needs.

You speak from experience when you say caregiving will take over your mom's life. It will. We all know that. If your mom finally decides to take her mother into her home be as supportive as you can be. Be there for your mom. I get the impression you live out of state but phone calls and cards are always nice and are a good way to let someone know you're there for them. Your mom is lucky she has such a concerned daughter.