Well, that depends on what you mean. Nahuel said it would be seven and a half years or so. By that time she will have aged to about 18.
So depending on what you mean by "how old will she be?" I have to ask if you mean literally or looks to be. Literally she will be between 7 1/2 to 8 years old. She will look like she is 18 and have the mentality and maturity of an adult.