You do not have to be a vampire to get the quest Kindred Judgement. Kindred Judgement can be completed both as the Vampire faction and the Dawnguard faction.
Kindred Judgement is initiated after getting Auriel's Bow in "Touching the Sky". There are no choice which locks you out of Kindred Judgement.
However, there are a noted bug that may cause the quest not to start.
- Picking up the bow may not start the quest.
- Having Garmr or CuSith killed may cause this. Console commands can be used on PC in order to resolve this issue.
This is taken from http://elderscrolls.wikia.com/wiki/Kindred_Judgment
Another issue occurs for the Dawnguard faction. After Isran gives his speech, the Dawnguard does not move out. This occurs when one member of the Dawnguard is away (for example, if one member is a steward for your house). The group will only start to move once all the members have gathered. In this case, the away member will slowly travel to Fort Dawnguard, so the player can simply "wait" a few hours.
The following thread highlights some other possible solutions. I do not know whether the solutions will work.