Auto insurance issues with my mother

So in December of 2023 my mom helped me get a car her being the main one on the car so ofc she has to be on insurance as well. Fast forward to now, my little sister has gotten her drivers license she’s 18 yrs and my insurance geico realized that she got a drivers license but has no car/insurance under her name. Her current cars insurance is under my mother’s name since if it were under my sisters name the insurance would be too high. Anyways, since geico noticed that and we have the same address on our licenses they automatically added her as a driver to my policy, making my insurance go up super high. My mother contacted me saying that I will have to find a solution such as me finding a new insurance changing my address (I have no bills under my new address yet) etc. or saying I will have to pay this insurance myself since it’s not her car it’s mine. I find it pretty unfair that I have to pay for this since one I never asked them to do that , but my mother or sister also didn’t ask them to do that geico took it upon themselves. My little sister currently pays for her car insurance that is under my mom’s name so my mom thinks it’s unfair for her to pay her own plus paying me for her part of the insurance on my policy. Also my mother and I contacted geico and they said they will need proof of my sisters insurance that’s under her name for them to remove her but again her insurance isn’t under her name. I live in the state of Nevada and would really like some advice on what to do!!