1. First of all, you should respect the decision of your good friend. Although you may think that she made the wrong decision, the final decision should be made by herself. If she doesn't want to listen to your advice and talk to you about this topic, you should respect her choice.
If your best friend wants to talk about her feelings, you should listen to her opinion. Don't try to make decisions for her, but provide support and understanding.
If you think her situation is dangerous, such as her partner's violence against her or controlling her behavior, you should take action. You can help her find professional help or resources, such as a domestic violence hotline or a women's rescue agency.
Finally, if you really think she made a wrong decision, you should choose a suitable time and way to talk about this topic. You can provide your opinions and reasons, but don't try to force her to make any decision. You can tell her your worries, but the final decision is up to her.
In a word, you should respect your best friend's decision, listen to her feelings and give her support and understanding. If her condition is in danger, you should take action to ask for help. If you think she has made a wrong decision, you can provide your opinions and reasons, but the final decision is still made by her.