Isit possible for someone who can't sing at all to learn to sing? I'm not talking learning to sing like Idina Menzel or anything, but enough that people don't cover their ears at the first note? Are there singing instructors who specialize specifically in bad singers? My sister is a classically trained opera singer and does musical theatre who has been able to belt since she could talk, so my experience with vocal lessons has been watching hers.
By the way, I was told once that I'm good at matching pitch, if that helps any.
Well. Depends on How bad is your ear and how bad you are trying to make a sound in pitch (tone.)
If you cannot make any sound in tone (pitch) you will need a lots of ear training and sight and singing lessons before to start your voice training.
If you develop your ear, in the way you can follow a simple melody, or if you can follow scales and intervals and sing their sounds with out a problem then you can start training your voice.
Then be patient to star a long journey. After that, everything else is about technique. Ask your sister, she will tell you how long time takes to develop a safety vocal technique.
If your sister is an opera singer, I don't think you would be "SO BAD " at singing. Generally, these kind of talents runs in the family.
I am classically trained, I am an Opera Singer, But my Mother and father have never being trained and both were excellent singers My mom even sound like a trained Soprano. My sisters can sing in tune and My brother too. My aunts and cousins nephews and my nice, my grand parents too. Just one of my grand mothers can't sing at all.
So maybe you have a talented voice too like your sister and you just feel shy in front of her.
Find a voice teacher who works with beginners, and never try to sound like any one else, discover your own sound and work hard to improve and develop a good voice technique
Good Luck!