the secret admirer mistake

so i started painting a month ago at the local studio and there's this girl who sits beside me almost every session. we're always chatting but nothing serious or personal, you know? last week our instructor asked us to do a self-portrait as a challenge for two weeks. instead of my face, i've been working on her portrait because she has such an interesting expression in class one day. now it feels weird showing up every session and seeing her right there but also not telling her what i did. am i just overthinking this? should i tell her or pretend like nothing happened? i really need advice here.