When my sister hit a financial low point (had to come to me for money because she could not afford to have her cat who was in pain euthanized), I felt I had to do something. After turning to the SA boards here for advise, I had a calm & loving & BRIEF chat with her explaining my concerns. I then offered to buy Suze Orman's "Women & Money" book for her, and offered to give her any advice I could. She took me up on the book, not on the advice.
Since then, she has made quite a bit of progress. I know she will never save as much as I think she should, and she still spends more money on unnecessary things than I think is wise in her situation, but she has managed to put away money for emergencies and save for short-term goals. So overall I'd say my gift was successful.
Based on my own experience, this is my advice:
1. Make the gift an "extra" gift. Give it now, with no expectation of reciproicity. Go ahead and give what you normally would for Christmas or birthday, so they don't feel they are getting "cheated" out of a fun gift.
2. Give the gift in a form that you think will appeal to the recipient. I thought my sister would like Suze's style (flamboyant, with an emphasis on feelings & the appeal to "woman power") and I was right. I also know that my sister is a voracious reader, so a book would be best. But if your recipients haven;t cracked a book since high school but love to watch TV, then a DVD would be better received. I also knew a "beginner's" PF book would be best for my sister.
3. When you give the gift, give a brief, calm, non-preachy explanation of why you are giving it. Express your concern, and let them know the gift is because you love them.
4. Offer additional advice or support, but then you're just gonna have to stand back and let them come to you (or not) if they want to. Give the gift and then let them decide what to do with it.
Good luck!!!