Uuh, you are pretty tall. Im jealous lol
I would lose 3-4 that would bring your bmi under 17.5
I'm 5'9" 109.7, bmi 16.2
I think you should play safe and get to 110lb and stay there. If you want you can even afford to get to 115lb and you would be lovely.
I am 157 (5'1), around 84kg (185lb) 😭