Correct. You deploy her and she act as a witch. Attacking and Slowing. In 7 seconds you get to use her ability. The ability switches her focus from damage to healing. Once the 40% bonus wears off (10 seconds) it will go on cooldown for 15 (Total of 25 seconds). You can then cast the ability again to make her focus on dealing damage, and getting a 40% damage boost for 10 seconds.