a new relation on the family tree

I had a video call with my sister yesterday. She was looking after her 3 year-old grand daughter, my great-niece, and was trying to explain to her who it was she was talking to on Nanny's phone screen. "It's your great-uncle...", and she showed me to her, waving hello at her and trying to engage her in conversation. Blank look. I thought maybe this was a bit of a mouthful (and concept) for a 3 year old to grasp, so suggested to my sister that perhaps I could be known as 'gruncle'. Haha, we thought. Gruncle. A mash-up of Great and Uncle. Relevant, funny sounding, and an easier term for young, newly starting speakers to grasp, surely? My great-niece was more on board with this term, and started happily singing 'gruncle, gruncle, la la-laaa' to herself in the background as my sister and I were chatting. Then she added her own twist. She grabbed the phone off her Nan, her little snotty face suddenly appeared in extreme close-up on my screen, and she was happily sing-shouting to me…