we usually go once a year but this year my mom went crazy and we went 3 times in 6 months...lol
how to convince her...hmmm...
how about tell her that you need to take as many family vacations as you can before you get into college? or something like that
My family dosn't even go every year! we have gone to Disney World 4 times in my whole life, and I am 14. In 2003, we are going to Florida but it won't be the same without Disney World! We are going to the Keys.
We go A LOT. I go usually at least once a month. Sometimes for day trips. Sometimes overnight. We go to stay overnight 4-5 times a year.
As for convincing your mom, you can always try the "I'll work really hard to help pay for it" That always tells my parents that I'm very serious about. Just sit down with your mom and tell her you want to go even just for a short trip!
We don't even go once a year, but we try to go every few years. Definitely try the "This will be our last chance to take a family vacation before I go to college." Parents seem to go for that.