How can caregivers get support from rest of family members?

Your profile states that your mother is in independent living. I assume you and any other caregivers (since you used the plural term) live close to her and visit regularly?

Perhaps you could make a list of support tasks that you and the other caregivers feel need to be done ...grocery shopping, medical visits, other outings, etc. Circulate the list among the family members and ask which tasks they can help with.

You ask for it. Make it clear you need help. Ask each person for one day a week.

Thanks Gardenartist, there's only one caregiver, i make a typo mistakes.