My grandma does squats and stretching exercises daily and feels younger than her age of 91. Here are her longevity tips.

• My grandmother Kathleen is 91 and feels much younger than other people her age.
• She makes sure to get movement every day, values strong friendships, and has many passions.

My grandmother, Kathleen, was born in England in 1932. After marrying a Royal Marine Commando and having two little girls, she immigrated to the United States at 28, where she added a little boy to her brood.

She is a cancer survivor, a retired cardiopulmonary technician, and a true character. She loves to shop, everything from thrift stores to luxury boutiques in San Francisco, and she swears more than the average grandparent, but softly and in an English accent, which often makes most people smile.

Kathleen believes in the health benefits of daily movement and strong female friendships, and she's also the ultimate romantic.

I've heard her, on multiple occasions, refer to other people her age as "old people" because she feels much younger than her years. She recently told me, "It doesn't matter how old you get, you're still the same person. Sure, you can't do some of the same things. You don't get whistled at anymore, which is a big plus, but you're still the same person inside."

Here are her lifestyle tips for not only a long life but a happy one, too.

Stay moving

"If you don't use it, you lose it." I can't count the number of times I've heard my grandmother say this. Following her own advice, Kathleen gets up every morning "stiff as a board" and stretches to limber up. Then, she moves on to her exercises, which include squats and working with light weights. In total, her morning routine takes about 20 minutes.

Daily movement helps Kathleen feel more youthful, and she seems to be on to something, as research indicates that exercise may actually slow down cell aging.

Develop strong female friendships

Chatty, warm, and funny, my grandmother makes friends wherever she goes. From her lifelong mates in England to the newer pals she's made in the US, she values each and every one of them.

She specifically values her friendships with women because of the bonds created by shared experiences. Over the years, she and her girlfriends have raised kids together, helped each other through illness and grief, and spent countless afternoons shopping, laughing, and sipping white wine. Kathleen will never forget one particular adventure in 1949 when she and a few female friends cycled from London's Euston Station to Windsor Castle and back. No small feat, the journey is almost 30 miles each way.

These strong female friendships benefit Kathleen in more ways than one. Studies show that friendships aren't just for fun; they're also good for your health.

Though it can be hard to make friends as adults, Kathleen says it's actually a lot simpler than you might think — and others out there are looking for friends, too. 'You just have to reach out to people. And before you know it, you have more friends,' she said. A sense of humor helps, too.

Be a romantic

It's quite evident that my grandmother loves love. She's been married three times, and she now has a boyfriend. He's also 91. She's never let the end of a marriage or the loss of a husband deter her from finding happiness again, and my grandmother and her boyfriend share many adventures together, like road trips from California to both Florida and Idaho. They love going to the movies, trying new restaurants, and watching British crime television shows on BritBox.

Romantic relationships can improve physical and mental health by lowering stress levels, preventing depression, leading to a longer lifespan, and much more. Plus, a dinner date night is always fun!

Always get ready for the day

I'll admit, this is one tip I probably need to incorporate into my daily routine. Often working in sweatpants and a comfy hoodie, my grandmother always gets ready for the day. Though I often spend the day working in sweatpants and a comfy hoodie, my grandmother always gets ready for the day, no matter what she's doing. She does her hair, puts on a cute outfit, and doesn't forget her jewelry. Getting dressed up makes Kathleen feel good. "When you go out, you dress nice. Period," she said.

For days when you wake up not feeling so peppy, Kathleen offers a tip that works for her: "Jump in the shower and wash your hair. You'll feel like a million dollars."

Read, read, read

Luckily for book lovers like my grandmother, reading has many health-related benefits, including preventing cognitive decline as we age. Plus, it's fun. There's nothing quite like losing yourself in a good book. Let yourself escape to new places, meet new people, and learn about different cultures.

Kathleen reads every night before going to bed. She also loves to read outside in her colorful backyard, believing that fresh air can do wonders for your mood. She enjoys various genres and authors, but a few of her favorites are Maeve Binchy and Rosamunde Pilcher.

Find things you're passionate about

While family is very important to my grandmother, she believes you must make time for yourself, apart from kids and significant others. She has always made time to volunteer, starting at age 10 in England, where she offered her time to the St. John's Ambulance Brigade. Her duties included wrapping bandages, and once, when she was 15, she got to ride in an ambulance with a patient.

Over the years, Kathleen's passion for volunteering included raising money for St. Judes and volunteer firefighters, among many other charities. She's also the first person to help a friend, send a care package, or hop on the phone for a chat when you need it most.

Above all, be kind

Of all Kathleen's tips for a long and happy life, this one is probably the simplest: "The most important thing to be is to be kind. It's so easy to be kind."

Not only a benefit to those you meet, experts suggest that being kind can benefit your physical and mental health by improving mood, reducing stress, and possibly leading to longer lifespans.

So, follow in Kathleen's footsteps and practice a little kindness when you can. You never know who might need it.