Brooke Shields' eldest daughter, Rowan Henchy, has opened up about her lengthy diabetes battle

She told PEOPLE: "First of all, I lost a lot of weight, really rapidly.

"But I was eating two meals [for] each meal. I was consuming so much food and I was just losing weight even faster the more I would eat.

"Another thing is you're constantly peeing.

"And then my eyesight started to go and then I got a really bad toe infection. So these are blaring, red flags for undiagnosed Type 1 diabetes."

Rowan recalled having a "rough year" but was comforted by her friends and her sister, Grier, 18, who attended the same all-girls high school.

She shared: "The first couple months were rough because all my friends at my old school were hanging out with boys and I decided to go to an all-girls school and then I got diagnosed with Type 1 diabetes. So it was just a rough year all in all.

"That school ended up being my favourite place and I have my best friends in the world and Grier ended up going there, so it worked out.

"But freshman year - it sucked. It was more of just like, 'This happened. How can I continue living my life and not be all sad and depressed?'"

Brooke admits she felt "helpless" and said her daughter had to "grow up quickly".

She said: "I was feeling helpless because we didn't know what to do and then she became completely autonomous with it. She was old enough to administer the insulin to herself. And as a 14-year-old, giving yourself shots multiple times a day is a very quick maturation process. She became very competent. She had to grow up quickly."

Rowan has learned how to cope with managing her illness and is thankful to the new technology that helps suffers monitor their sugar levels.

She added: "There were times I wished that I was diagnosed at 5 because I knew a life without it.

"But even from the four years that I've had it, there's already been so many advancements in technology."

"I have a pump on my stomach and a Dexcom patch on my stomach.

"It's a 24/7 job and I'm never off duty.

"But at the same time, it's at the back of my mind. It only controls my thoughts when my blood sugar is too high or too low. Regardless of whatever headache, you find a way around it. It's something that I have and it's now just about managing."

Brooke is raising awareness by starring in a film about a Type 1 sufferer called 'Quarter'.