I need help with convincing mom to let me have a ferret?

my dad is all for it but my mom... well, she says no. i did my research and i know what i need to get and to do for the ferret. i made a video for my mom so i can show her how cute they are i have not shown her yet so i also have a fact sheet to back up the video i am trying to show im more responsible by cleaning my room without her asking and doing what she wants me to do the first time she tells me to (which is big for me cuz i hardly do the stuff im doing now!) i have mentioned i want one without trying to be annoying. what else could i do that will help my chances? i know what i need to do for a ferret play wise and heath and care wise im going to do more research just to make sure. so any help?