A: She wouldn't attend the weekly assembly.
B: Oh, she wouldn't, wouldn't she?
(Quoted from Treasury of English Grammar, by Liu Yi)
Oh, he isn't ready, isn't he? [rarely used]
(Quoted from English Q & A, by Prof. Wu Bingzhong)
So you don't like my cooking, don't you?
So you won't speak to me, won't you?
So he wouldn't come, wouldn't he?
(Quoted from Ho's Complete English Grammar, by Ho Limin)
Same-way question tags
Although the basic structure of tag questions is positive-negative or negative-positive, it is sometime possible to use a positive-positive or negative-negative structure. We use same-way question tags to express interest, surprise, anger etc, and not to make real questions.
- So you're having a baby, are you? That's wonderful!
- She wants to marry him, does she? Some chance!
- So you think that's amusing, do you? Think again.
Negative-negative tag questions usually sound rather hostile:
- So you don't like my looks, don't you?
http://www.englishclub.com/grammar/verbs-questions-tag.htm