Do they have phones with text? Do they have email?
Most people I know who do neither live in these places nor speak Yiddish (though there are exceptions- then again, I put that in the same category as my friends who speak Russian, Spanish and Farsi). Yiddish just isn’t nearly as common among non-chassidish girls as it is among non-chassidish boys- my brother’s in fifth grade and he can scrape by in Yiddish just from picking it up, and I wouldn’t understand the first thing you’d say to me.