Well if you believe that your siblings are being treated poorly or their health is in jeopardy, you could call CPS.

Other than that we can’t tell what’s really happening. Your expectations of being provided with footage of the incidents or updates of their medical appointments are somewhat unusual. Your mother isn’t obligated to update you. You don’t have any guardianship of these children.

Again if you are concerned, call CPS. Other than that your rights in regards to these kids are limited or in fact non existent. I understand you care about your siblings but some of your expectations are unrealistic. You “questioning” your mother isn’t going to get you far

PS I wonder if your mom doesn’t want you to babysit them anymore because the injured one was engaged in dangerous behaviors. Why were they allowed to jump from the stairs on to the couch? That’s pretty out there. Typically jumping on the furniture is not a good idea under any circumstances and surely is a terrible idea after knee injury.