How to tell if she is actually interested or just being polite?

When someone listens attentively and splits the bill twice but asks no spontaneous questions, you are looking at a polite participant rather than an engaged partner. That lack of curiosity is the tell. People who want this to go further tend to wonder about you back, even when they are shy or anxious about parental pressure. If she only responds when given an opening, she is likely performing the bare minimum of social obligation to avoid conflict at home. The only way to stop guessing is to test the waters directly, which carries the real risk of making things awkward or getting a flat rejection. Ask her point-blank what she actually wants out of these meetings. You can say something like, I want to make sure you are here because you actually want to be and not just because our parents set this up. Saying that out loud is uncomfortable because it strips away the polite coffee shop chat and forces an honest answer. If she stammers, looks relieved, or admits she is just going through the motions, you have your answer without needing to decode her silence anymore. If she pushes back and actually starts investing in the conversation, you will know she is choosing to be there. Either outcome saves you from wasting weeks guessing whether her smiles mean anything real.