Early milestones CAN be associated with giftedness but are not required and do not definitely indicate giftedness.
Motor milestones obviously might be tied to physical giftedness - but I would suggest that advanced comprehension and intention is required in order to make early motor milestones happen.
My HG+ DD hated tummy time, she learned to roll very young in order to get off her tummy, the second you put her on her tummy she'd flip back over. At 4 months old she visibly decided she wanted to cross the room, and instantly changed tactics - the second you put her down she'd flip onto her tummy and start swimming. It took her about a month to master commando crawling. She was a menace in the cupboards from 5 months old. She's low tone and hypermobile, retrospectively it's quite an amazing feat that she could crawl at 5 months old and it was absolutely driven by desire to get somewhere and investigate more than by the need/desire for physical activity. In our OTs assessment there are many things my DD does (monkey bars for example) that simply should not be possible with the body she has, but clearly she is intellectually able to compensate for what does not come naturally and she's very determined.
