Could be laziness at her age... again Pooka generally peed in the easiest place at any given time when we first got her (got her at 8 weeks). Then at some point she decided she actually liked the litter tray and started using it. I know it's not much help, but I honestly have no idea what made her change her mind about where to go. I actually think she suddenly just decided to be clean, because when she knows she'll be running about with my two boys she seems to hold it in, then runs over to their litter trays and uses those....