Empathetically: This implies a deep understanding and sharing of someone's feelings.
Compassionately: This emphasizes a feeling of pity and concern for someone's suffering.
Kindly: This conveys a gentle and caring attitude.
Understandingly: This highlights the ability to grasp someone's perspective and situation.
Considerately: This implies taking someone's feelings into account and acting with care.
With empathy: This is a more direct and straightforward way of expressing the same idea as "sympathetically."
The best synonym will depend on the specific context and the nuance you wish to convey.