I may sound a little bit cruel, but I think it would be perfectly acceptable for her to attend Caylee's funeral, PROVIDED that she be REQUIRED to view the remains in the casket.
again the mistake I feel we make is believing KC is just like "us". She isn't. This would not phase her in the least. It would be like her seeing an old worn out pair of shoes that she thought she had gotten rid of for good. They have no DEEP attachments to any living breathing thing, which of course, allows them to do what they do. If she had the capacity to "care", as you suggest, she Never could have done what it appears she has done.