We have raised two bilingual children. Norwegian / English.
I am from Norway, dh is Polish, and we lived in the UK. We did not press them on the Polish, but we speak English at home.
Even though we lived in London, DS1 was only picking up Norwegian. He went to an English nursery, and dh spoke English to him, yet he preferred Norwegian. He would reply to dh in very short yes no style sentences.
When he was 3, he was a very lonely child, as he still only spoke Norwegian. No amounts of cbeebies, books and films changed this. Then his brother was born. We got a polish au pair, and I started talking to DS1 in English rather than Norwegian, so the au pair should understand what I had said/instructed. He was confused at first, but within a month he had supressed all his Norwegian, and spoke like a Londoner!
For the next six months he refused Norwegian. It would come back to him slowly when visiting grandparents in Norway, but on the whole, he spoke English.
Ds2 did not pick up much Norwegian. Due to the aupair, and the language at home being English to a larger degree than when ds1 was born, he did not really pick up any Norwegian. When he was 2 we got a Norwegian Au pair, hoping it would help. Along with Norwegian stories, and films, we spoke Norwegian at home. He seemed to understand some of it at least, but would reply in English.
When ds1 was 6 and ds2 3, we moved to Norway. Ds1 picked up Norwegian and became truly bilinugal within a month. For ds2, who had never really known the language before, it took a little longer, about 6 months.
We have lived in Norway for two years now, and we are working really hard on keeping English alive for our kids. We watch bbc i player, read english books, watch english films, and talk english at home. So far it is working, but I have noticed ds1 is losing his london accent, and ds2 is making some really funny and creative grammar at times!
Dont give up! 14 months is still young, just expose her to English as much as you can, you cant really do more than that. Holidays to grandparents works wonders, too!