Milestones

Can someone please explain to me how they decide what age a baby should be doing what? My LO is almost 1 (in two days) I have read she should point and show me things by now but when I google most articles say by 18 months? She will look when I point but doesn’t really point to anything. She loves watching me clap or play peek a boo and laughs but doesn’t attempt to do it herself. My 3 year old daughter was always very early hitting all her milestones so I’m just not sure when to be concerned. I know I shouldn’t compare but it’s hard not to. She did just learn to crawl a few weeks ago (ped said that is to be expected because she’s a big baby). I’m wondering if she’s too busy exploring to really try and make the connections she should apparently be making by now. I will say she observes like crazy. Always watching what’s going on around her. I plan on bringing this up to her pediatrician next week, just wondering if anyone is else has input.