I think some of the criticisms of her family are over the top. Kei met with her with her family for over 3 and a half hours a week ago. Yes, the meeting was in private. I think that's fine.
https://www.youtube.com/watch?v=_Ne_ulnWWeI
Her father spoke in favor of her marriage publicly.
https://www.youtube.com/watch?v=jqAsZ197L98
I think the normal engagement rights were a bridge too far because they involve both families and it seems as if he wants to avoid Kei's mom.
The toughest part is the next few months. Because she is now a commoner, she can not stay overnight in her parent's home. She has moved into her own apartment. I think Kei will join her there. The Japanese are making noises about not giving them any security protections there. (I think she's more likely to be attacked there than in New York.) She has to apply for a passport in her new name and the Japanese government can stall this. Despite how absolutely vile much of Japan has been to them there is a movement to stop her from moving abroad!
She also needs a US visa; I expect this will be provided very quickly.
As a princess, Mako got a monthly grant. She also had a job--which is unusual. I suspect she has been squirreling away every penny she can for the last 3 years.
Fordham Law posted when he started studies there. There were comments from Japanese posters denouncing Fordham for accepting him. Several said he was not the Princess' fiance and the school obviously did not check with the Japanese Foreign Service before posting his false claim that he was. Others said he was not academically qualified to study at any law school and had forged his qualifications. Another said that Fordham should be aware that it had ruined its reputation in Japan and no decent Japanese citizen would ever enroll in it again.
I feel sorriest for the daughter of the emperor. There is nobody noble for her to marry either.