This is all correct, and in the case of double strike your creature would have dealt 4 damage when the Tusker dealt its 3.
When a creature has double/first strike there is a first strike combat damage step before the normal combat damage step, abilities trigger and resolve and players can cast spells as normal during this step.
So I was wondering if a first strike/double strike and lifelink creature attacks with Cradle of Vitality, is my thinking correct?
Example: I have Cradle of Vitality, Knight of Meadowgrain and i attack into a Kalonian Tusker. In the first strike phase, i deal 2 damage to Kalonian Tusker, gain 2 life, and on the stack, i pay for Cradle of Vitality trigger, making Knight of Meadowgrain a 4/4. Then regular damage step goes, Kalonian Tusker deals 3 damage to Knight of Meadowgrain, which survives damage, then combat resolving with both creatures still alive.
Thanks
When a creature has double/first strike there is a first strike combat damage step before the normal combat damage step, abilities trigger and resolve and players can cast spells as normal during this step.