It would help to know what went wrong with those other cats as this is likely to be what your mom will use as an objection. One thing to know about cats is that they require a lot of freedom to move around and do as they please most of the time, even if you keep it indoors as a housecat. So the other members of the family have to want it around, too, because it will try and want to interact with them and not just you.
Do not just get one on your own without her permission. If you end up having to give the cat away then that it a bad thing to put the cat through. A cat should be a lifelong commitment.
EDIT: That is sort of an irrational reason to get rid of the cat. Sounds like your mother didn't really want the cat in the first place and so used any excuse that came along to get rid of it. That makes convincing her even harder.
Since the rest of the family is fine with it, then I would try to get them to help convince her to let you get a cat. Having others on your side and telling her they are is always a plus. All the points you've made here about being able to care for it are valid and should be used, plus you can say that you've learned from having a cat before and would be better at taking care of one this time around.
My mom is the same way due to fear. Some people can not commit themselves to a pet due to fear of them or fear of loss or plain fear of having to clean up their mess or having to be obligated to the pet. My mom has all those fears and although she would never be mean to one in any way she can not stand a cat to touch her.
You an try but sometimes no means no and we have to deal with that word. It may be a blessing in disquise. You will leave home at some point in your life or seperation in some way from your family atsome point in your life will come.
However, it is then that you may be able to get the neatest cat ever. Iam sure she loves you so hang in there. People sometimes do change their minds and some won't.
It is a part of growing up. I agree with every answer. Where did your other cats go?
I feel maybe you need to wait and earn more about cats.
You first have to find why it is that she won't let you have a pet and then tell her that you can do whatever it is she thinks you cant do (unless you cant do it, then don't kill yourself over it), or if she just doesn't want to have one at home then try to convinse her how much you really want this. Find out why she won't let you.
Okay the last answer is a lie. They live about 5-10 years. And just say mommy do you love me?
Then show her pictures and bring it up around her friends. Thats what im doing in the same situation. But this is to get a second one for me.
And if she says she loves you,say 'then why cant you get me the one thing I really want. Please?!
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.