Hmm sounds a bit like it's not just a language issue but interlaced with your position in the household / relationship with your daughter etc. I think you feel reather powerless in terms of influencing your child in the direction you'd like her to head (and I don't blame you).
Maybe you need to de-emphasize language and first find a project that you two can do alone together. Be it reading, cycling, taking a course (it's summer, what about sailing etc). I think if you can find an activity where you do something alone together you'll be able to bond over something that is just for the two of you and language will naturally become part of that.
My dad was Anglo-Quebecois but he really wanted his daughters to speak french (we lived in Vancouver). I still remember sitting on his lap as he read us stories in french -- we had so many books in french you'd have thought french was his first language. I also equally remember reading an illustrated version of The Hobbit (in English) with him and being thrilled, scared, and excited to read the next chapter every night. The point was not what language we were reading in, but getting us reading an exciting story, and more importantly, spending time alone with our dad at the end of our day.
He also made efforts to do activities with my sister and I and one-on-one time with just him. He took us fishing, camping, tennis, sailing, to the amusement park etc. On Easter he'd always make a big deal of it and organise a scavenger hunt.
My parents also chose to send us to a bilingual school, and my mum continued to send us there up until graduation -- was my French perfect? No, but it became high-functioning enough considering I lived in a region where more Chinese/Japanese is heard than french.
When I think back on my childhood I remember these experiences with my dad -- and I don't remember thinking of it as torture of sitting there having to read in French, it was moments that I got to spend with my Dad -- and he went out of his way to create these moments because many nights of the week he was often home after we had even gone to bed.
My Dad died when I was 6 -- but having had these one on one (or two on one with my sister) moments with him created enduring memories (and influenced my beliefs even). Spending time reading with him created a lifelong interest in books and language.
Sitting down to read a book can be a magical time, but if you turn it into homework the magic is lost. You need to find books that will open up her imagination. There are lists everywhere for age appropriate books -- you can buy off of Amazon no problem. And you can buy english and spanish versions and read chapter by chapter in different languages if you like. In fact to start with I'd almost suggest you start by reading in Spanish together at first if that is what interests her more at the moment, and then slowly introduce English books. Perhaps find a series of books (there are so many for kids these days, and read some of the books in Spanish and some in English).
For inspiration you can read about this father and daughter that read together every night until she went to university:
http://www.nytimes.com/2010/03/21/fashion/21GenB.html?pagewanted=all
