Not sure how to respond to coworker about possible microaggressions
I (34f) work in an office that only has one other person (56f) in it most of the time. We sometimes share personal drama with each other, but our offices are across the suite from each other, so we have plenty of space and don't talk a lot theoughout the day. That is to say, we are friendly, but not friends.
This doesn't happen often, but occasionally my coworker will say things to me that are delivered as friendly commentary, but come across as an attempt at a subtle dig. I never know if it's intentional, and I don't know how to respond.
Previously, these comments have usually been about my weight or my body. I am short and plus sized, but I eat very healthy most of the time - lots of veggies, fruit, and fish. My coworker has repeatedly said things to me like "I don't understand how you eat the way you do and still aren't skinny" or "if I ate like you, I would be skinny". Sometimes she'll tell me stories about her family or friends, and she always makes sure to describe the people's bodies to me in ways like "she's your size" or "she's probably built like you but taller".
Friday, I was stung by a wasp on the face. The area is swollen and had some fluid trapped in it, which drained last night, but it's still red and inflamed. This morning, my coworker walked into my office, said good morning, and immediately said "wow, you have a huge blemish on your face. I'm not used to seeing you with blemishes". I didn't know how to respond, so just told her what happened.
It doesn't hurt my feelings that she does this, but it irritates me that I have to deal with it. I don't know how to professionally or politely respond to her. I'm starting to feel like she's purposely saying these things as an attempt at being covertly bitchy, in a mean girl kind of way, but I can't really tell. Regardless, I would appreciate any advice on how to handle these situations.