No problem. If you have the installation paperwork, that might list the ratings of your aux heat and emergency heat. You other option is to kill the power and remove the door on the air handler. There should be something inside that say what you have. you can also count the number of heater elements to help get an idea. What I have (electric furnace) is basically an air handler with the heat strips. I have a coil for A/C, but no heat pump installed. In my case, I have 4 elements that are 6kW each (24kW total). They come on in stages using sequencers. This is to prevent a large current draw by kicking them all on at once. My inside unit is fed through a 150A breaker. My ouside unit (A/C only) is 30A.
It is hard to know what you have without further informatiion. It could be that only part of your aux heat is working. For instance, say you have 2-7kW elements (14kW total). You could have a bad sequencer, bad element, or wiring that is preventing the other element from kicking on. It is hard to say.
Basically, the heat pump is sized on your heat load. This depends on your location, size of house, number of windows, insulation, etc. With a heat pump, the performance drops as it gets colder outside. The heat loss then increases with colder temperatures. At some point (say 35*), the heat pump cannot keep up, so the aux heat kicks on to make up the difference. How much aux heat is needed depends on how cold it gets, the size/efficiency of the heat pump, etc. This is why you can buy say a 5-ton heat pump, but have a wide range of aux heat choices (say 0 kW to 20 kW).
Do you think there is a problem? Is it not heating the house enough? If you are worried that there may be a problem with your aux heat, see if you can get more info on how many elements you have and what size. Then maybe with some pictures of the setup, I can help you do some further testing.