A.L.
If you are in North Austin, check out Bananahead swim school. They are in Round Rock. Small business, with only one teacher - Coach Clint.
Pseudo-private lessons, with class sizes topping out at three students per class. Month-to-month - no long-term commitment. In an indoor pool, too, so he offers classes all year long.
We loved going there, but even with the new tollways, it was a 20 to 30 minute drive from our home depending on traffic, and we just couldn't fit it in with dance lessons AND Girl Scouts AND homework. We stayed until my daughter showed she could swim well unassisted, but didn't stay to perfect her technique. The distance is really the only reason we're not still going there.