It looks like share price was ~10$ at the start (2018 to 2020) and is currently ~13$ so presumable your family could cash out right now for a 30% profit.
$10 was the SPAC before they merged to become NKLA. The merger was announced in March 2020 (when the price jumped to low teens) and completed in June (when the hype made it go up to $60s).
