What do you do if someone you aren't close to says "I love you"?

So my boyfriend’s grandma is a very sweet lady and tries to treat me as one of her grandchildren. She tells me to call her grandma (in their language), gives me a hug, says “I miss you” when she hasn’t seen me in a while. When she was hospitalized I did cry when I visited because I felt terrible for her and seeing my bf’s family sad.

Anyways, I’m not that close to her. I barely even talk to her because she doesn’t speak much English. She hugged me a couple times and said “I love you!” and I don’t say it back.

I’m not the type of person to even say “I love you” to my family except my boyfriend and my baby nephew. I’m not even that close to her so I feel it’s inappropriate to say “I love you too” even though I do care about her health. I find it awkward not saying anything back, haha. What would you do?!