Help friend curb barbs from her sister

DEAR AMY: I am friends with -- and frequently travel with -- a pair of sisters. At times, one sister makes nasty comments that indicate she thinks the other is stupid or clueless. This isn't the case. The other sister is a very bright, capable woman whose main flaw is not standing up for herself when she is verbally attacked. This makes me very uncomfortable. Occasionally, I have been the recipient of a stinging comment from the harsh sister, but I deflect the criticism right back in her direction. I would like to defend my friend from her sister's snarkiness, but I'm not sure how. Caught in the Middle

DEAR CAUGHT: This sister dynamic might be lifelong, powerful and resistant to your ability to affect it. However, you have the right to try to influence a dynamic that makes you uncomfortable.

This one sister sounds like a bully. If you three are together and she verbally attacks her sister, you should respond -- plainly, clearly and honestly.

You say, "I really like you, but I really don't like it when you do this. You can't be nasty to me and other people in front of me. I don't like it and I'd like you to stop." Privately, you should encourage the more passive sister to stand up for herself.

Because you have dealt with this successfully, you might help this sister by rehearsing responses with her.

DEAR AMY: "Helpful Grandma" was posting negative responses to her grandchildren's Facebook photos. Grandma is trying to parent her grandchildren. This is the parent's job, not Grandma's. I remind my children often that the Internet is forever, and to be extremely careful of what they post, because it can all come crashing down on them at a future job interview. If Grandma wants to share in her grandchildren's lives, she should do so without judgment, and pass off her comments to their parents who are better equipped to handle the situation.Not Facebooked in NY