Yes.If I was born into a well-off family, can I say ”I come from a well-off family”?
Yes, with the correction.Is it idiomatic?
I was born with a silver spoon in my mouth. <- idiom. This idiom is only used in certain contexts - it does not directly say that the family was wealthy - it suggests that the family was wealthy because your parents could afford the best things for you.And is there any other expression?