Minority language at home is the method we chose for us.
I'm native speaker of Spanish. My husband is English but speaks Spanish fluently, and we live in London.
From what I've read and seen, the age a child starts speaking varies depending on the child and anywhere between 12 months to 36 months is considered within the norm. Of course, if the child starts speaking around 12m or earlier would be considered an early speaker, and those at the end of the range would be called late speakers, and raise some worries from their parents up till the point they start talking.
My ds said what could be recognised as his first word at 15 months. It wasn't a proper word, but I could understand how he chose it to point at balls, anything that was round like a ball, and anything that rolled like a ball.
At 16m he said his first proper word in Spanish for water. Soon after that he also started using "mama" and "papa" properly when he called for us, not just babbling.
From then on, he started learning a new word a month, then every two weeks, then every week. By the time he was 23 months he knew a total of 110 words (97 in Spanish, 13 in English).
Then we went to my country for holiday and he had what is called the "language explosion" there, which occurs typically around 20 months according to the books. He learned about 10-20 new words per day, from talking with my parents and local people around. He learned verbs, and started combining words and making his first simple sentences of two words.
When we came back to the UK, in the next 3 months he progressed really quickly and was already talking in long sentences, having proper conversations and telling stories in the minority language.
I find this topic (language developing) fascinating and always read everything I can on multilingualism. I documented as accurate as I could his progress and that's why I can look back now and remember how it all started.
I'm sure your daughter will be fine and follow the same way.
Now, regarding the majority language, in our case that was the English.
He has been exposed to it since he was 8m old by going to nursery 2 days a week. At playgroups he didn't necessarily picked up any English as I spoke to him actively in the minority language no matter what. And I was also lucky to meet other parents with children of similar age who were also Spanish speakers.
I knew he could say a few words in English because at home he sometimes pointed at things and said them. But by the time he was 2y3m, a teacher at his nursery told me she was impressed because he finally had said "sit down" at nursery, and from this comment I realised he was not really talking at nursery because at home I knew he could say "sit down" since 5 months earlier. We then decided to read him one bed story in English sometimes (my husband), and I read him a book, sort of like a bilingual pictionary, and taught him vocabulary in English. He could already say the names of all the pictures in Spanish, I taught him how they call them at nursery. That was a turning point. About a month later he was already talking a lot, and eventually his teachers told me he was a chatter box in English as well.
So just play it by ear. By the time she goes to nursery/school, see how quickly/easy she picks up the other language. If you find she is struggling, you can give her a little help until she picks up the language and starts managing herself. Then stop any help for the majority language and focus on the minority language. That's how we did it.