Haha your mum is obviously computer illiterate, or else thinks the rest of the world is extremely dumb. If anyone wanted to know anything about you they already would. Your obviously in early highschool or late primary, gaging simply from the nuances in your word choice and your situation with your parents. You are on your home computer (which will leave a specific signature with each post you leave anywhere on any forum). From the information you have already provided about living in the southern hemisphere and your temperature ranges plus the species of mantis youre looking to get (considering its the only mantid currently being advertised online on a site easily accessible to young people.), we can already see youre from Australia. Possibly (but unlikely) youre from a smaller island close by. From the temps in your home id guess youre living either somewhere down south, like ACT or Victoria or youre closer to the mountains, west of NSW.
There are only two users from Australia on here and neither of them are interested in hunting you down. Everyone else who is on the other side of the globe is probably similarly disinterested in paying for a flight to visit you. There is plenty of underage poontang to be found all around the world.