"I think every once in a while, a very, very young person who is burning both ends of the candle needs to have somebody say, `You know, you're going to pay the piper, you better slow down.' So I think it was good," the 68-year-old actress told "Access Hollywood" in an interview to air Tuesday.
In July, James G. Robinson, CEO of Morgan Creek Productions, chided Lohan, 20, in a letter for her behavior on a movie set and doubted her absence was related to heat exhaustion. "We are well aware that your ongoing all-night, heavy partying is the real reason for your so-called 'exhaustion,"' he wrote.
"She's in the magazines, so you always know what she's doing because you can just read about it in the tabloids," she says. "She parties all the time ... And you know, she's young and she can get away with it. But, you know, it's hard after a while to party very hard and work very hard. She learned that, I hope."
Lohan's publicist, Leslie Sloane, did not immediately return an e-mail from The Associated Press late Tuesday.
Lohan plays a troubled teen in "Georgia Rule," which co-stars Fonda and Felicity Huffman. The film, currently in production, is expected to be released next year.
Fonda is still sympathetic toward Lohan, who is estranged from her imprisoned father Michael Lohan.
"I just want to take her in my arms and hold her until she becomes grown-up," she says. "She's so young and she's so alone out there in the world in terms of structure and, you know, people to nurture her. And she's so talented."