Cassie, Maid in Training

Whenever Cassie, Maid in Training attacks with
three or more other creatures, she gains Indestructible and Lifelink until end of turn.
Whenever you gain life, put a +1/+1 counter
onto Cassie, Maid in Training.
Some become maids as they lack medicinal education.
Some become maids as they enjoy helping others keep
a clean house.