Although the diploma is useful to have, nothing beats actual experience. Depending on what she is interested in she could take up kennel work, work with an animal charity (which usually involves kennel work), grooming (for which training needs to be undertaken), veterinary nursing (which also needs training) - so my advice would be to get work in a kennels or other animal related establishment, and work her way up.
Unfortunately, even at the top of the tree in kennel and other animal related work, you still end up shovelling sh*t most of the time!
Other options would be to work with one of the animal charities such as Guide Dogs, Hearing Dogs, Assistance Dogs, etc, where the opportunities to progress are much better, and she could end up becoming either a trainer or helping to allocate dogs to owners.
If she is interested in more exotic animals, zoo work or wildlife park is another option. Again though, much of the time is spent shovelling the proverbial.