Every Wednesday from 10:30-11:30 a.m., Cook teaches her native language with seniors and staff as part of the Center's programs since August 2006.
"It's just something for them to do. A lot of our seniors can speak Tlinigit specifically but can't read it. Now they're learning how to read it," said director Tina Martin, of the Center.
As Cook is a senior at the Center, she's also a volunteer, freely donating her teaching time and visiting for lunch.
"We had such a struggle with some of us, but she's so patient and we all keep coming back. They're together; they can laugh and joke. There's a lot of fun, a lot of storytelling and it really helps them out completely," she said.
"If you don't say it right, it's completely a different word. Then they laugh at us and say you won't believe what you just said!" Martin said.
All seniors are welcome to join the program, ages 60 and up, she said.
A full-blooded Tlingit, Cook, 65, has lived all her life in Hoonah except when she went to Sheldon Jackson for high school.
She is part of the Raven clan or "T'akdeintaan."
Cook has never taught classes before, and as they were looking for a volunteer for Tlingit teachers, she found a place at the Center.
The classes work as a healing tool for the seniors. In Cook's age group, many quit speaking their native language, because in school they were reprimanded for it.
"I was one of them; I was told I couldn't speak it. After I went to school, I couldn't remember (Tlingit language). My mother lived until 92 and spoke to me in Tlingit and I answered in English. I didn't realize I was doing that," Cook said.
"I think what happened when I was going to school and they didn't want us to speak it, (was) I began to think something was wrong-so it stuck with me."
Cook's mother, Mary Wilson, was a prominent figure in the Tlingit culture, especially the dance performances.
While Cook is not a fluent speaker, she can read and say the language; she teaches students what she knows, and the process has been challenging for her as well. Several of the fluent students can speak the language but can't read it.
"I have four to five fluent speakers who are there to help me. I'm hoping some of the words and sentences come back to those who remember a little bit," she said.
"I just want the people in my age group and younger to carry it on, it's something that everyone keeps saying is dying out," Cook said.
"I read in a newspaper the other day just because you can speak Tlingit doesn't mean you can't teach it. I disagree with that. I teach them to speak better the correct way."
Cook is teaching students through the Tlingit sound system, out of a beginning learner's book, working through repetition.
"We go through that (book), and then introduce ourselves. Right now we're learning about food, and say a sentence in Tlingit words on things they like."
"We go through the sound system at the beginning of every class, then we review and add new things," she said.
Cook has given three tests, and progress has begun to show.
"Everybody has had fun so far. When I told them about the first test, they got worried," she said. "After they started doing the test, they got really excited and said it sounds like we're really speaking Tlingit."
"She stays low-key when her students make errors and keeps an even pace throughout our lessons: no rushing (and) no lagging," said student Rory Schneeberger.
"Genevieve Cook, whom I lovingly call "sensei,' Japanese for 'exalted teacher,' is marvelously patient and kind. She sings, too. Her sense of humor is most welcome in class where difficulties with pronunciation abound," she said.
The next step Cook hopes to work on is teaching to students to introduce themselves in Tlingit.
"It's a lot of fun, and I'm proud of them because you can tell a difference. We can go through the sound system and the review pretty fast (now)," Cook said.