Is there a table that shows daily calorie intake for weight maintenance for different weights?
I did a rough estimate and I think my gf eats about 2500 calories a day. She is not "actively" gaining, only letting her natural appetite loose, so I don't expect that number to increase.
At what weight can I expect her to plateau?
(Her height is 162-163cm, btw)

Its not that simple
Get her a dexa scan and figure it out, based on bmi, ffmi and fat percentage