You've noticed that your friend is acting a little strange. Perhaps she's not returning your calls or your conversations have seemed fairly superficial or strained lately. Maybe her personality has changed suddenly, or you are noticing some passive-aggressive vibes in her communication to you. Whatever the case, you can weather a friend in a funk by being patient and tactful.
Give Her Space
Maybe your friend is just in a funk and needs some space. Friendships naturally ebb and flow; you come together, you drift apart. It is the dance of human relationships. As close as you may be, your friend is entitled to her privacy, her space, and yes, her secrets. Perhaps she is experiencing stress in her job, her marriage or with her family. Just because she's acting weird doesn't mean you're the cause. Allow your friend to have the space she needs to process whatever she is going through before rushing in to fix the situation.
Trust Your Gut
If you've given your friend space and you notice that she is still behaving strangely toward you, there may be something wrong with the dynamic of your relationship, or perhaps she is harboring some kind of resentment toward you. Perhaps she is experiencing some emotional or psychological stress and as her friend, you are concerned about her. If you get the intuition that something is wrong, it probably is.
Schedule a Time to Talk
Invite your friend to meet up at a specific place at a specific time. You don't have to tell her that you want to talk about how she's been acting. You can simply say that you've missed her and that you want to catch up. If she's been isolated or distant lately, she may try to come up with an excuse not to meet up. Tell her that seeing her is very important to you, and ask her to pick a time when she is free for 30 minutes to an hour. Be willing to accommodate her schedule.
Confront with Compassion
If you've been feeling slighted by your friend's recent behavior, you might be feeling a little resentful and blown off. But, if you approach your conversation with resentment and bitterness toward your friend, assaulting her with blaming or accusatory language, she is likely to shut down even more, further isolating from you. Instead, confront her with compassion, open-mindedness and curiosity. You could say, "I've notice you've been a little distant and I wondered if I did something wrong," or "I've observed a change in you lately and I wanted to tell you that I'm here for you if anything is amiss in your life."
Once you've said your piece, it's now your turn to listen. Again, compassion and open-mindedness will prove much more helpful than will judgment and criticism. Allow her to speak without interruption and show her your support with gentle eye contact and physical touch, if appropriate. Be aware that you may not want to hear what she has to say. Maybe she wants to come clean about a resentment toward you. She may also not want to say anything at all. If your friend shuts you down by saying, "Oh, nothing. I'm just busy lately," or "I don't know why you'd think that," be willing to say that you must have been mistaken and close by saying that if your friend ever needs to talk that you'll be there for her.