Can you not change outfits yet or am I just dumb?
No, just undress her by increasing her lust meter.
Sadly the game has now been abandoned, so won't be getting any more updates :(
This dev had some amazing potential for sure, both this game and their Halloween one had some really nice pixel art and a lot of character to them.
Sadly they vanished a year ago on all their socials, so I wouldn't expect them to come back.