Cute used to describe a person? May work out in some cases, but in most it really will not for various reasons. She may feel you’re infantilizing her, you don’t find her appealing as a woman or appealing for the wrong reasons, you belittle her …
As many wrote, used to describe her choices it’s perfectly fine though.
If you’re looking for a way to express how this person makes you feel - for example a continuous stream of “awwwww” may be expressed by calling someone cute - rather describe your feeling: “I could fawn over you all day.” Ideally you also explain why, so it’s clear where this is coming from: “The way you dress is a perfect compliment to your outgoing personality. I really enjoy just watching you exist.”
Depending on who you want to be to this person and how far along on that road you are, my examples may work or be entirely out of question.