As a mom I can only share my personal experiences with you. You may share this with your mum if you wish.
It was the end of March 2004, and my son told me about his friend having a new pet snake. I listened curiously to him, as he was just so animated as he spoke of it. He told me how colorful it was, how friendly, how cool, etc.
He went on for 2 weeks asking for one, so I insisted if he was serious that he would have to read about them before I would consider letting him have one. He was 11 years old. We went to our library and sat at a table reading a few books. At this point I was even fascinated with the variety of colorful morphs. Then again I was a complete Tomboy when I was growing-up, and often would bring home reptiles to get a thrill from scaring my own mom. But I was still concerned about cost and proper care. As a young child my parents let me have green anoles, (which mom called chameleons)baby painted turtles, fish, etc. and usually they never lived real long because of improper care. Not my fault! I was too young and my parents were ignorant as to their care.
Well I finally agreed to let him have one, and my reasons were the following:
1. Corns are well recommended snakes for a first-time owner.
2. After INITIAL cost of supplies, the cost was minimal for a pet. (never intended to breed... this was an accident and could have been avoided IF I would have housed the snakes separately... like most suggest.
3. Vet fees were not going to be a regular cost like that of owning a dog/cat, but were considered in budget for health problems and emergencies.
4. SMELL was nearly non-existant. That was a huge positive. Usually the snakes poo in the corners of the tank, and this can be easily cleaned-up with paper towel. You don't have to dump all the bedding out each cleaning. Fresh water is essential so that must be a regular chore.
5. Tank I purchased was checked thoroughly for escape routes. It had a sliding screen lid that snapped shut AND provided a place on the front where I used a bread-tie to make sure it was secure. I checked screen often to make sure it wasn't coming loose. Never place anything heavy on top of screen so that the screen doesn't rip or come loose in any way. So as far as escaping... I was satisfied.
6. As far as handling the snake, I had strict rules in the beginning for the safety of the snakes and my son. You will have to come up with those as each person/household is different. For example he couldn't have friends over and be "showing off" his new pets. They could be admired from the tank. He also had to prove to me he could properly handle the snake. This assured me he wouldn't harm the snake, or accidentally drop it. I was assured in a few short weeks that the snake wouldn't be a "lost snake". I always told him that IF they ever escaped, that you could consider them DEAD. (We have very large air ducts that lead to a HOT wood stove / furnace combination).
I was only intending on buying him one snake. We had the viv all set-up and ready to go. When I saw that chocolate sweetie though, I decided to buy two snakes. Against recommendations I housed them together. They were best buddies up until this spring when they (at age 3) became mates. Of course this can be avoided.
I had issues at first, but really grew to like... and then love the little guys. I got used to feeding too! But you can assure your mom that you will do all care. Compared to the care a dog, cat, horse, even a hamster takes... I think this has been the easiest pet to care for.
Since I assume you will have your snake's enclosure in your room, there shouldn't be a problem with "freaking out" visitors. Ours was at first in his bedroom, but then they grew into a larger tank that was in the family room. Some visitors had a real problem until I covered the tank.
It has been over 3 years and they haven't once escaped, needed a vet, or costed much money... other than the money I wanted to spend on their fancy vivs. This cost can be as little, or as much as you want it to be after the basic enclosure and equipment is purchased. It has been a great experience and I am so glad I said yes to my son. I took into consideration that these snakes live a long time. I figured I would take care of them if he ever couldn't... such as if he were away at college/university. I would always have a back-up person capable of caring for your snake IF EVER you cannot. Also make that budget out. Find out the cost for the enclosure and each item you need. Factor in the cost of the mice too. Make sure you can afford this. Show this to your mum to show her you have taken this all into consideration too.
Inform/educate yourself well. Then be prepared to have a heart 2 heart with your mum. I hope this helps. Let me know how it goes.
Sincerely, Heather