"I'll leave the swearing to the Jane Fondas"

This quote by Irene Dunne is a humorous means of sharing her viewpoint that she will not be using blasphemy. She is suggesting that she will not be using any type of swear word, yet rather leaving that to the Jane Fondas of the world. This quote is likely a reference to Jane Fonda's outspokenness and also her readiness to speak her mind, also if it suggests making use of blasphemy. Dunne is suggesting that she will certainly not be adhering to in Fonda's footsteps as well as will certainly rather be much more reserved in her language. This quote is a lighthearted way of revealing Dunne's viewpoint that she will not be using obscenity, and also rather will be leaving that to the extra outspoken individuals like Jane Fonda.