DD was easy to manage as long as she was constantly held and constantly had a boob in her mouth.
She was alert and social as a newborn, but also very easily overstimulated. When she was 3 wks old, we took her to a loud family gathering, and instead of sleeping through it like DS would have, she screamed frantically until an hour after we got her home. She was also a terrible sleeper, with lots of night wakings, until around age 2.5 or 3.
Overall, she just seemed like an older person trapped in a baby's body. Slightly early on milestones- sat alone at 4 mos, cruised on furniture at 7 mos, crawled at 9 mos, walked at 10 mos. She started saying words at 5.5 months, and after that she was a bit easier, as she could finally communicate what she wanted to us. Followed instructions before 9 mos. She much preferred pointing and communicating to us what she wanted, rather than going and getting it herself by rolling or crawling to it. She started stimming when excited at 6 mos, and has continued it to this day. Possibly mild spd, never evaluated for it (lots of auditory, tactile, texture sensitivities from a young age).
DS (8 mos) so far seems much more like a "typical baby". He seems bright, but other than being very motivated to explore his environment and fairly early on his milestones, nothing super out of the ordinary. He was alert as a newborn, but not *spooky alert* like DD was. He's very social and a pleasure to have around, regardless of whether he ends up being gifted like big sis