She may not like it, but would that be such a big deal? Friends can't have the same opinions about everything, and maybe a discussion about why you like the show and she doesn't could be both fun and informative?

I tend to watch all Sherlock Holmes adaptations I can get hold of, and while I didn't like Elementary I did watch it first. I haven't seen the great wank war people are talking about. Seems like a limited number of idiots on tumblr? I have a tumblr with which I follow some Sherlock blogs, and I haven't even seen a mention of Elementary.