Oddly, there are people that actually offer their services for funerals & wakes which just seems tasteless to me. BUT, I can understand having some SIMPLE bits like Sponge Bunnies and some very simple coin type stuff for the kids that are there and "lost" as they often get. I'd not be twisting balloons or juggling, but doing some simple tricks to help cheer them up or otherwise occupy their minds while the adults are doing their thing, MIGHT be acceptable. The thing is, you really need to make a judgement call as to what is appropriate, when and where. . . I'd pull the kids off to the side if practical, or when you find one that's feeling shy, etc. do a little something for that child. . . be prepared to give things away but ask the parent before giving a kid candy of any sort and of course, be wise when it comes to small items (choking hazards).
That's about as far as I'd push things and I certainly wouldn't be doing anything tied to the Paranormal.