Kwende, Pride of Femeref

• WOTC Official Reminder Textofficial rules
  Double strike — This creature deals both first strike and regular combat damage.

• WWizards of the Coast2018-04-27
  Official Ruling
  A creature with first strike and double strike deals combat damage the same as a creature with double strike. It doesn't deal damage three times or before other creatures with first strike.
• WWizards of the Coast2018-04-27
  Official Ruling
  If a creature loses double strike after first strike damage is dealt, it won't deal normal combat damage.
• WWizards of the Coast2018-04-27
  Official Ruling
  If a creature you control gains first strike after Kwende has entered the battlefield, that creature also gains double strike.

Rulings via Scryfall