Preemies / Premature babies

Hi mummies who birthed preemies, just want to ask when our babies know that we are their mummies and also reciprocate smiles? I keep feeling anxious that my bottle fed baby would prefer others over me. When I pump, I put my baby with my helper because she cries a lot when I don't give her attention. She is now corrected age 3 months. Appreciate any responses :)