Our blueberry shrubs are pollinated by bumblebees. I see them out there every spring, working the blooms. To get the most fruit, it helps to have two or more shrubs, of different varieties. The size of the blueberry shrub is under your control, if you are willing to prune. There are dwarf and lowbush varieties available. My experience with lowbush has been that they are healthy, attractive plants, but they don't produce much fruit. Maybe a cup of berries per season. If you want to get a good harvest, it would be best to plant highbush varieties, and prune the shrubs as necessary to keep them sized to your needs.

Does there need to be a male and a female? And how big do the highbush varieties grow naturally?

No such thing as male/feamale, I believe. Just get 2 different varieties.

They grow 4-6 ft. high.

Thanks for the replies