My thoughts? She needs insulin to bring down the high number. If you are afraid to do that at night, wait unntil morning, so you can keep an eye on the process. Ketones will come down pretty quickly as her glucose levels regulate.
As newly diagnosed, please be aware that being ill can have dramatic effects on blood glucose. Most diabetics on insulin will require additional insulin when sick.
Did the doctor provide a correction ratio for you, i.e. 1 unit of fast acting insulin reduces glucose by 50 points? That is the number used to calculate how much insulin to use as a correction. Also, I find that I like to avoid food when correcting, especially when ill. The food really can interfer with the results.
Let us know how she does.