It's never too late!
Saying that if you go full on speaking to her in your first language she may well rebell against it.
Obviously you have to judge the situation and apply what you think is best, but I would recommend trying the following, in your first language:
You tube language songs for this age- I would try and watch some of these with her, sing them with her and try and use the words from the songs in real life situations. Also, I have found this is good to do in the car when she doesn't have many other alternatives.
Background music in your house- play this as much as possible: when she is getting dressed, in the bath, getting ready for bed. "Would you like to go to bed now or stay up late and learn to sing a song with me?"
Speaking to other members of your family, and letting her hear this, in your first language.
Cartoons- if they are interesting enough I guess she would want to watch them.
Play groups in your language
Obviously visiting the country if this is an option.
I would think that after, say 100 hours of the above, she will start to learn.