Barrel Racing Saddles

My niece is interested in barrel racing, but must first learn to ride, it will be necessary to separate stool or mother can just buy a Barrel Racing and use it for trails and Barrel? If necessary separate please explain the difference if I let my sister know why two saddles are required. Thank you.

The main difference between saddles barrel trail saddles are the seats. Barrel saddles deeper seats, and the horns and are lighter. That way, when you make a sharp turn, you can lean back in a sense.
Trail saddles are heavier.
Just because you have the trails does not mean that you must use a trail saddle, a saddle can work.
Same for barrel racing.
A saddle can do fine. There are a wide variety of seats to choose from, so I go to a store of tactics and sit in different saddles to find one you like. Remember that you will use the saddle a lot, you want to be comfortable in the saddle and you want the saddle to fit your horse.

There are many different things between the two stools. A barrel racing saddle has a horn, usually tall and thin for optimum grip around your tower. Bear Trap barrel saddles are highly recommended. The swell or fork is turned in higher and almost kiss you. Barrel saddles also have a deep seat and high cantle. Calipers are also thinner and more manageable.
Trail saddles are made primarily for comfort. They usually have a shorter large horn that does not get in the way, but can be used to wrap things around (rope, reins etc.) The seat is made for comfort and cantle varies each drawing or model either high or low. The brackets are generally larger and broader at the base of support right foot.
I have a barrel racing saddle Bear Trap and I walk in her path and I've never had a problem comfort wise. I recommend buying a saddle barrel. If the stools are comfortable path, the individual design does not necessarily many people to just buy a saddle for the trail, unless Trail Ride. Hope this helps, good luck shopping saddle!
I would also recommend getting your saddle for your horse after the purchase. This may resolve pain and other problems in your horse before they occur.