The actress is reportedly raising her daughter Apple, nine, and Moses, seven, to be bilingual and often encourages them not to speak to each other and her in English.
While at Cameron Diaz's Beverley Hills home for the wedding of her assistant Jesse Lutz on October 12, she was heard urging them to put their language skills to good use.
An eye witness told Us Weekly: "Gwyneth reminded them throughout the party. At one point, Apple came to her table and asking, in Spanish, if she could sit on her lap."
The 41-year-old, who is married to Coldplay singer Chris Martin, 36, recently defended her parenting choices in an interview with the UK's Red magazine.
She said: "The idea of 'Oh God, if I don't show up to this concert, all the other mums are going to think I'm terrible', Well, so f**king what. "It's like, when I'm with my kids, I give them everything I have. And when I'm not, I give whatever I'm doing everything I have. And that's my work/life balance."
Gwyneth continued: "I've made it work for me, but it doesn't matter what my specific thing is. It's like, what's your specific thing? How do you want your life to look?
"It doesn't matter what anyone else thinks. It matters what you think of yourself. And what your children think ... I'd say, do what is right for you and don't give a sh*t what anyone else thinks."