I'll just assume since they were planning this, that they prepared ahead by siphoning money from their families for their future. That they secretly learned how to cook and care for themselves, that they made a clean get away plan and know where to go. And that they know how to cover their trail so that they can't be tracked down once people find out they're missing. Would be pretty stupid if 2 noble ladies (even if one of them suffers from Isekaitis) with no idea how to care for themselves just eloped off into the sunset. But as it ends on a cliffhanger of just them running away together, these questions are probably never going to be answered.