One little thing, in my mind Teddy was adopted by Harry when he was a baby. Either his grandmother died or she was unable to care for him.
Disclaimer- All characters belong to J.K. Rowling
Age 2)
"Hey Teddy, there's someone you have to meet," Ginny beckoned to the toddler.
The little boy slid off of the hard, plastic hospital chair and followed her on chubby, toddler legs.
Inside of the small hospital room were more people than seemed possible. Harry came over and lifted Teddy up above all of the adult's heads. Teddy was then able to see Aunt Fleur was on a bed in the back of the room. She was holding some small bundle. Suddenly the bundle moved, Fleur shifted the blankets around it and a small face appeared.
The next thing he knew, the room was filled with a terrible wailing sound. It seemed to be coming from the thing in Fleur's arms.
Uncle Bill looked up at Teddy, "That's Victiore Ted, she's your new cousin."
Teddy peered closed at the screeching bundle. He couldn't help thinking that the tiny, red screaming thing that created this awful noise certainly didn't seem like ant girl he'd ever met.
It would take weeks before Teddy would even consent to be near Victiore. Months before he would let her hold his finger in his tiny fist. It wasn't until days before her first birthday when she screamed her first word, "Teddy!" that he admitted that she was kinda, maybe, sorta, a tiny, little bit cool.