Sounds to me like the pump is very overpowered, she should have a maximum of 1hp for that pool, probably even a 1/2hp would suffice.
There are several other things to look at too though:
1. How much water is in the pool? it should be AT LEAST half way up the skimmer, any lower and the "tornado" will suck in air.
2. How much sand is in the filter? if there is not enough, you will get a higher pressure at the return.