Sally Field and Madison Ferris talk about playing mother and daughter in Broadway's The Glass Menagerie and their off-stage bond

Before the action starts on stage in director Sam Gold’s acclaimed Broadway revival of Tennessee Williams’ iconic 1945 memory play The Glass Menagerie, stars Sally Field and Madison Ferris have to get up the stairs.

It’s harder than it sounds, at least for Field.

Entering from the aisles of New York City’s Belasco Theatre, she first waits while Ferris — a 25-year-old actress with muscular dystrophy making her professional debut in the production — dismounts her wheelchair and slowly moves her body up to the stage. As the audience sits in silence, Field then folds up Ferris’ chair and carries it up the steps.

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“It’s actually really hard for me,” the 70-year-old Oscar winner tells PEOPLE. “I mean, it’s much easier for her than it is for me. I’m the one people ought to worry about, in reality. Because I’ve said, ‘Look — if I let go of this chair, just duck.’ ”

“At the beginning of the first previews when we were first doing it, I had bruises all over my leg,” she adds. “I’ve learned to do it a bit better but still — there’s always something that will happen. Maddie’s much more in control than I am.”

Ferris laughs, looking back at Field. “She said, ‘It might come down one day.’ I’m glad I go up first.”

"The Glass Menagerie" Opening Night - After Party
Sally Field and Madison Ferris
| Credit: Bruce Glikas/FilmMagic

The two are sitting with PEOPLE backstage in Ferris’ dressing room, nearly a half hour before curtain time. Though over a thousand people are waiting to see them in the audience, neither look nervous. They’re all smiles, recounting how they met and giggling with one another like old friends.

In The Glass Menagerie, the relationship between their mother and daughter characters isn’t exactly peaceful. Amanda, played by Field, tends to air on the overbearing and controlling side — pushing her daughter Laura (Ferris) into trying to meet a “gentleman caller.”

Laura, meanwhile, is headstrong and stubborn — keenly aware of her physical limitations and resigned to the realities of her life (and her mother’s delusion).

"The Glass Menagerie" Opening Night - Curtain Call
Madison Ferris and Sally Field
| Credit: Walter McBride/WireImage

Their relationship on stage may be tense, but off stage, the two are close. “She touches me more off stage than she does on,” Ferris says. “It centers me a lot — especially right before we go up the stairs. I have to smell her hand lotion before.”

“Touches is the word,” Field explains. “She knows I’m possessed with holding her hand or putting my hands all over her all the time. Her hair, her hands, her body — when it’s on stage too, it just seems to be the way it is. I just love it. I love the closeness of taking her hand and seeing her face — I usually put my face in her hair.”

“We always have just had this sort of physical connection to each other,” she adds. “We’re always eying each other.”

The Glass Menagerie
Madison Ferris and Sally Field

They first met during Ferris’ final audition, when she was one of two actresses reading alongside Field for the role. It didn’t take long for them to get comfortable with one another.

“The first time we met she complimented my underwear,” Ferris dishes. “It took all my energy to not say ‘They’re Fruit of the Loom — I can get you a set!’ ”

“Well they were turquoise and gorgeous — the color of your dress,” Field shoots back, laughing. “I think you did say that and I went out and got some, I swear to God!”

Laughter pops up a lot when talking to Field and Ferris. The friends and costars are joyful — Ferris confessing how she often teases Field’s character on stage and Field confessing her love for dirty jokes (“Know if I tell a joke, it’s got to be filthy beyond your wildest dreams,” she says).

That may surprise some, about the actress known for playing the Flying Nun, but not Ferris. “She’s a spitfire,” Ferris says. “I think people have an idea of Sally being this sweet mother, and she is — but she’s also, she’s feisty.”

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Ferris – the first actress in a wheelchair to play a leading role on Broadway — may be a newcomer to the scene, but Field says the young actress is a talent to be reckoned with.

“I never, ever hedged my bet with her,” Field says. “I met her toe-to-toe. As an actor, I have 53 years in the saddle and she has somewhat less. But I never, ever pulled my punches. Not one single bit. And she never ducked, ever.”

“She’s so willing to be raw — willing to just be an emotionally available, just constantly,” Field continues. “There doesn’t seem to be any armor, and that’s rare under any circumstances. But then there’s also a part within that rawness that says, ‘Don’t think for one minute I need you to take care of me.’ ”

The Glass Menagerie is now playing through July 2.