DEAR ABBY: I am 11. My sister, “Brittany,” is 9. She always tries to make me feel dumb and little. She makes fun of everything I do and cracks rude comments about me. She kisses up to everyone else and makes them think she’s an angel.

I am fed up with Brittany’s smart-alecky comments and rudeness. She constantly annoys me because we have the same room. She thinks it’s a huge joke that I am going through puberty and holds her nose around me all the time.

I have tried talking to her, my parents, my grandparents, and anyone else who will listen. They think we are “just being sisters” and that I complain too much. Help! – FED UP IN GREENVILLE, S.C.

DEAR FED UP: Your sister is acting like a brat because she is only 9, and she’s jealous of you. Please try to keep that in mind when she makes you feel “dumb” and “little,” because you are neither.

When Brittany teases you about going through puberty, remind her that in a few years, she will be going through the exact same thing – and how will she like you holding your nose around her?

Puberty is a difficult time under the best circumstances, and sharing a room with a little pest can make it even more so. Perhaps that room could be rearranged so that you both have some degree of privacy? Think about it and discuss it with your mother, because it is doable.

DEAR ABBY: I recently ended a three-year relationship, and afterward I found out my ex had fathered a child while we were together. This is not the reason I ended the relationship because I didn’t know about it until after it was over.

When I told our mutual friends that I knew, a few of them told me they had known the whole time, but were “giving him the opportunity to be a man and tell me himself.” I feel hurt and betrayed because no one told me the truth. One of these “friends” was my own sister – which has obviously put a strain on our relationship. What should I do? – BETRAYED IN FORT SMITH, ARK.

DEAR BETRAYED: Although you were told the reason they kept silent was to “give (your ex) the opportunity to be a man and tell you himself,” it may also have been that they didn’t want to hurt you. In other words, it was a misguided effort to protect you. So please try to forgive them. (That includes your sister.) And be grateful to the Lord above that you didn’t waste any more time on that philandering jerk.

DEAR ABBY: I always read the advice you give everyone. I am depressed. Since childhood, I have always been a problem child. I always have this sense of loneliness in me. Due to that, I’m not very active. I never want to marry. I wish to remain alone. According to our customs here in Kuwait, marriage is compulsory. But I do not want to marry!

I am a business student, and I wish to take a psychology course so I can be away from my parents and family. I want to be by myself. I just hate being with them. Am I doing the right thing? – MIDDLE EASTERN GIRL

DEAR MIDDLE EASTERN GIRL: I agree with you that the reason you feel the way you do could be depression. Depression and feelings of isolation often feed upon each other – each making the other worse.

I see no harm in your taking a psychology course; such courses can be helpful. However, if there is a student health center at your school, my advice is to talk to a counselor there about your feelings. You need professional help beyond what I can offer in a letter.

Dear Abby is written by Abigail Van Buren, also known as Jeanne Phillips, and was founded by her mother, Pauline Phillips. Write Dear Abby at www.DearAbby.com or P.O. Box 69440, Los Angeles, CA 90069.