Hello, Mira33 ,
Use the Peacful Home Sachet powders to lay around in their home and inn their front yard and up to their door.http://www.luckymojo.com/peacefulhome.html
You can also mix the bath crystals with water and spray it in and around their home
If you can bury the candle remains, I would bury it in their back yard to keep peace there.
Front yard is to bring in and back is to keep it there.
Also, If you cannot bury the candle remains no their, don't worry too about it. Just remember that your prayers over your candle will help tremendously. And so will the sugar jar or the honey jar (which I prefer the honey jar because it is a more solid binding).
Now here is an old Hoodoo trick also: Mix 3 very small spoonfuls of sugar with Holy Water (from a church). Sprinkle it in and around their home. That helps tremendously also
Wishing you the very best