If it is basic skills like mask clearing,manually inflating, droping weights,and kit doning in the water I think she is lucky to get that extra practice in the gear she will be using after cert. Besides all of those snorkeling skills,we also taught our daughter not to ever hold her breath underwater because I was already a diver when she learned to swim. When she was 5 I over heard her tell a friend that she wasn't doing it right because she was suppose to blow bubbles when she swam underwater. Should I have waited 8 years for a scuba intructor to ingrain that into her 2 weeks before she was in the open ocean? I think the skills that are locked into your muscle memory can be the difference of the outcome of an incident. More often then not people don't practice those simple life saving basics after certification because they either don't want to keep their buddies waiting while they do them or they want to spend the time doing the fun stuff, not drills. How many times have we read death reports where the person forgot to manually inflate and to drop their weights. Over confidence is when you do something 4 times, in class, and think you will think of it in an emergency. Every second spent practicing those is seconds well spent. What would he teach her different from the instuctor. Wether to turn air on all the way on or to back off some? Where to clip the gauges? Like all agree on that anyway. You don't get good trim and bouyancy from a class, you get it from practice.
You do not need to be scuba rescue certified to save someone from drowning in your pool. How many millions of pool owners do you think have that cert. We took a red cross class the first week we moved into a house with a pool.