I also have 2.5 children of which the 2.0 are girls. We have been telling them since they were little girls that we wanted them to be 15, barefoot, pregnant, and out of the house. It worked, the oldest (severely handicapped) is in college and working on her second novel while living at home and the youngest is away at college, studying to get into pre-med, and has gone as far as wearing a "promise ring" with a hazy date planned another 4-5 years into the future. We used reverse psychology and it worked well with these two girls.

Now about that 0.5, I don't think it will work, but we'll figure out something!