It is supposed to happen this year if she can manage to take hormones long enough to create some breast tissue. Since she has never taken hormones she is terrible about taking them regularly. I have certainly offered.
If you're willing to help and she can use transdermal estrogen patches, such as Estraderm, Climara, Vivelle. A good starting dose for a preop ladyboy would be the 50 mcg/hr patch, The patch is applied once or twice a week depending on the brand and should not be applied to the same spot twice in a row.
These have the advantage of easy to remember dosing - just mark x's on the calendar the days to change the patch, and are less harmful to the liver as the estrogen goes directly into the blood stream, without having the go through the liver first (if taken by the oral route).