First things first, if you think your car has a v4 you need to do a shit ton more researching about cars before you attempt anything near a motor swap or have someone do it for you. Second, I don't think your sister's Protege has a v6 because it wasn't even an option.

Third. Here's some advice for you. The common view with 3rd gen Proteges is we don't really have any options for swaps. That being said, the motor in the protege isn't the best candidate for boost either unless you build the block. I would advise you to just do some small stuff on the car now and keep it N/A (naturally aspirated aka non-turbo). Intake, header, exhaust, some light suspension work, etc. This will let you get to know the car better and you'll get a little more performance out of it as well.

Also, check out Mazda Forums It's a huge mazda forum and the people there can help you out with just about anything that has to do with a Protege. Good luck.