Don't know why she is doing this now!!

My 2 and half year old bitch has started licking her mums ears as well as sniffing at her rear end too. She has just finished a bit of a phantom pregnancy (although she was mated but it never took).
She did lick her mums ears as a pup,so much so we had to separate them at night as she was licking so much that mums ears were getting infected and not healing due to constant licking.
Have checked Amber(her mum) and there is no sign of ear infection or any sign of her coming into season so don't know why Izzy is at these areas again

Any ideas???