A H-1B status is ended on the date the employment is terminated. In practice, USCIS may grant a transfer if there is a very brief "gap" which can be justified. In the H-1B layoff cases, the alien worker may consider filing premimum processing ASAP.
An immediate transfer to H-4 may be a solution to maintain the non-immigrant status. Once the alien uses the EAD to work, she would lose the non-immigrant status.