Question Regarding Emoyment history

Hello,

Question I have for everybody here.

My wife has been provided a tentative start date as a RN for the VA.

She was unfortunately fired from her previous job. On form “SF852024” it asks for her employment history.

Our question: Her previous supervisor and her did not have the best relationship, but the prior supervisors have had nothing short of praise for her work. We feel that putting her previous supervisor will not do her any good on her application. Are we allowed to put down other supervisors and not the most current one? Will they eventually contact HR to contact the current supervisor?

Thank you!