Here is a different prospective.
Sometimes you just don’t convince parent you respect their wishes / rules, not saying that by educating your mom and being responsible she would not warm up to the idea but it is a possibility that you need to take in consideration as well.
Growing up my parents let me any anything (birds, hamsters, turtles etc) except for the one thing I wanted the most a snake.
The good news is when you are truly passionate it never goes away and when you are on your own you can finally live your passion.
Now I have no idea how old you are since in one thread you are mentioning that you are a biologist and in this one you are apparently living with your mom.
If you are old enough to be a biologist then you should be old enough to be on your own and therefore own a snake without needing anyone’s approval.
If you are a minor living under your mother’s roof you can either convince her or not.
The things that will need to be addressed are
First and foremost educating her about the animal you wish to own.
Proving her that YOU will be responsible, this means provide for your animals need which includes financial needs (food, vet bills etc)
Understanding that the animal you plan on acquiring is a long time commitment 30 years or more, what if you go to college will she be stuck with YOUR snake?
Ect
Once you address all those points if she still refuses then you need to respect her wish.