UnUsed H1b can be used in future?

Hi this is for my wife, She filed her H1B extension in NOV 2018 and after few days we filed her F2 visa for change of status. In march 2019 her H1B extension got approved , followed after 3 days her F2 also got approved. As per latest approval she is on F2 now. Now my question is, in future when she filed a change of status back to H1B.

  1. Can she used her approved H1B dates which is unused ?
  2. If she need to go to H1B does she need to file a new H1B lottery or just change of status ?


Within the 6 years from her last valid H1 expiration date, she can file for a non-quota H1B petition.