Here are some compound and complex sentences formed from the provided sentences:

1. **Complex**: Katya took up karate when she was seven years old because she was interested in it.
**Compound**: Katya was interested in karate, so she took it up when she was seven years old.

2. **Complex**: Because her father is a professional karate instructor, he taught her karate, and she progressed quickly to become the junior regional champion.
**Compound**: Her father is a professional karate instructor, and he taught her karate; as a result, she progressed quickly and soon became the junior regional champion.

3. **Complex**: Although she did karate with other children who were the same age as her, none of them was as good as her, which made her feel dissatisfied.
**Compound**: She did karate with other children, but none of them was as good as her, so she felt dissatisfied.

4. **Complex**: Last year, she participated in the national championship, but she did not win because she was injured during one of the matches.
**Compound**: She participated in the national championship last year, but she did not win because she was injured during one of the matches.

5. **Complex**: She hopes to become a professional karate instructor and work in the same sports center as her father because he has too many students.
**Compound**: She hopes to become a professional karate instructor, and she also hopes to work in the same sports center as her father, but he has too many students.

6. **Complex**: Some of her father's students have been studying karate for several years, and her father thinks they would benefit from a different teacher since they are too familiar with his style of karate.
**Compound**: Some of her father's students have been studying karate for several years, so her father thinks they would benefit from a different teacher, as they are too familiar with his style of karate.