、。
Mother likes tea, but I like coffee.
Literal
Mother [topic-は] tea [subject-が] is-liked but, I [topic-は] coffee [subject-が] is-liked.
A parallel double-topic structure: each clause has its own は-marked topic, and けれども is the (slightly more formal than けど) adversative conjunction joining them. Both clauses use the 好き + が pattern. The parallelism is the point — Japanese is happy to make contrast explicit with repeated は where English might drop the second subject.