Rules are different depending on whether you are referring to Fairs, market livestock, and breed shows. Each organization regulates itself.
You need to check with your local fair rules and also with the state and county rules governing fairs in your state and county. You can do this either online, or request a printed copy of the rues from the different Fairs.
Most fairs will not allow a child to show large livestock under 9 years old. The child must turn 9 by the first of the year that the show is held. Small stock can be entered by children age 5 and older.
Large livestock classifications are sheep, goats (market and dairy), cattle, equines, etc.
Small stock includes poultry and rabbits.
4-H will not allow youth under 9 to show large livestock. FFA is middle school and high school so have no worries there. Grange has different age limitations but all organizations and fairs must abide by the State, County and Local Rules, whichever is stricter.
All work, feeding, pen cleaning, moving the animal, shearing, hoof clipping, etc. in a youth show MUST be done by the child. If the parent needs to shear the animal do it at home before bringing the animal to the Fair. If parents fit the animal at the Fair, or are doing the work, it can be grounds for a complaint and disqualification.
Breeding shows are governed by the breed/species organizations putting on the show. They do not have age rules about exhibitors as long as the child can physically restrain the animal. Breeding shows are for registered animals of that species or breed. However, remember that the exhibitors at breeding shows are there to win because this increases the value of their animals. They will be less receptive to a child that can't control her animal or upsets the show. Large breed shows in some species are business for some of these breeders. However, many of these breeding shows also have youth shows where children can enter and are cut some slack. They also often have showmanship tips and seminars.
At this point, I would encourage Cassandra to halter break the 6 month old ewe and work with her. Have her do as much of the sheep work as possible since that will get her familiar with doing it when she goes to an actual show.
One problem with sheep shows is that they only have 3 age classes for sheep. Early lambs, late lambs and yearlings. Occasionally they have a stud ram class. Ewes are expected to be in the field lambing after yearling age. Dairy goats and cows have a much longer show life since most of their judging points are based on dairy structure and udder development - which can't be judged until they are in milk.
Go ahead and work with Cassandra on showmanship with her ewe since everything she learns now will be used when she goes to a show with other registered sheep. To find sheep shows, go online. Most of them are advertised. There is a large livestock show in Fort Worth every year and lots of other sheep shows around TX so start taking her to shows to watch the exhibitors and how the sheep are shown.
By the way, market lambs are shown without a halter by only the exhibiting child. Breeding sheep shows allow 2 persons in the ring - one to lead the lamb on halter and stack it up in front, the second to stack the rear legs and help. Go figure! LOL
