The pattern is the same every time. You get home, you write, she answers, and for a week it feels like the holiday never ended. Then the messages get shorter. Then they stop. It is not that either of you changed your mind. It is that the conversation costs more than it gives once the language is in the way.
At the bar you had gestures, a shared table and a friend who spoke a little English. On a phone you have text, and text has to be understood. When every message needs a translator, replies get slower, then rarer, and each of you reads the silence as the other losing interest.
She has a job, a family and a phone full of people. What she does not have is time to fight a translator for you. Make the reading easy and the rest is the same as any friendship over distance: turn up regularly, be interesting, and mean it.