I press my eyes closed to hide my precious corneas from the penetrating light.

who describes their eyes as 'precious corneas'? Did she recently get a lasik eye surgery and constantly needs to protect her eyes or something?

pressing my head against my hand, the rough skin scratches my temple and I don't feel very ladylike

Unless she's the kind who's so adamant about "being a woman" or whatever, it's very random for her to be like "i am not ladylike" just because her hand is a bit calloused. But I doubt that's the kind of woman you're writing about.

The shower-head spits water at me that runs across my whole body much like Jonathan's hands

that sounds so funny. I think you're trying to imply that she misses Jonathan or something. Are you? Otherwise, most women wouldn't compare showering to being touched by their man lmao

I wipe the mirror and uncover the face its hiding. After so many years I still seem surprised at how I look sometimes, not in a bad way or anything, I just appreciate the things that make me, me. The small nose with a rounded end that Jonathan calls a cherry, I wonder what he'd call these lips then.

This makes me think that the woman is trying to hide something from Jonathan. The usual woman won't think about what their male partner thinks when they wear makeup, unless she's wearing makeup to hide her insecurities and hide from the world in general.

a red so intense MAC probably used some sort of condensed blood.

the brand is very specific. I know you tried to empathize with the female character by pulling up a specific brand of makeup but it doesn't add to the story. In other words, it feels forced.

Your narration makes it sound like the woman thinks about and caters to Jonathan a lot, and he might be possibly controlling abusive. Or that she's just very insecure about her appearance/sexuality to Jonathan. If that's what you're going for, then you did okay. However, something tells me that this isn't what you're going for.