I know that you have mentioned before that your children were a little slow to reach their developmental milestones. My baby is 11 months old and is still not crawling. She rolls over and has excellent direction; and she has just started getting up on her hands and knees and rocking, but no crawling; and for sure no pulling up or standing. She has a few sounds, but no consistent words like mama or dada.
I'm wondering at what point I should start being concerned. (Well, more concerned than the near-constant mommy-worry that we all have.) She has been behind from the start in her gross motor skills, so I'm not extraordinarily surprised that she is where she is, but people are asking about it more often and I don't really know how to address it. I don't really feel like I need to address it to randoms who ask; but it is on my mind.
I know that babies develop at their own rates, but I guess I'm looking for reassurance that she really is okay and that others have been in similar situations.
Indeed, my kids have been "late end of normal" in their development. In a group of babies, my baby would be the one lying there like an enormous larva while the other babies skittered all over the floor.
Rob didn't crawl until he was 12 months old. Elizabeth didn't walk until she was 17 months old---and if she'd done it 2 days later, I would have had to say 18 months old. At 7.5 months, Henry has rolled over maybe a dozen times and never on purpose. NONE of my kids have been able to say as many words as they're supposed to be able to say on baby/toddler charts. They are all late, late, late.
I'm sorry, but the only way I can give reassurance here is to bring out some serious bragging. Saying "and they're turning out fine!" is insufficient: pretty much all parents think their children are brilliant and amazing, and for all you know my kids are drooling their way through school as I look on them fondly and tell you everything's fine, perfectly fine! So I must say more, but I will keep it brief: on national standardized tests, Rob and William are both coming up as top of the class. Also, I'm pleased to report that both of them can walk AND talk AND roll over.
So when SHOULD you worry? Because I am a chronic worrier (ever since reading Laura Ingalls Wilder books as a child, I've been worried that we will be in such a terrible blizzard we will not be able to get back to the house from the barn) (we don't have a barn, nor have I ever lived anywhere with a barn) (but if we did, I would totally have a guide rope stretching between them), I like to turn over this kind of worrying to my pediatrician. I say to him outright, "I worry about everything. But I'm not going to OFFICIALLY worry until you tell me to worry." And about three times he's said, "It's not time to WORRY, but it's time to do a little extra investigation," and we do, and everything is fine. He says that, in general, as long as a child is continuing to make progress along the developmental timeline (even if the progress is slower and/or later than usual), everything is still fine.
I have been annoyed over the years by how SURPRISED people act at what is actually still within the normal range of development. "OH!" they say. "She's still not WALKING?" And their eyes get darty with surprise and alarm. "What does the DOCTOR say?" Or maybe someone says, "Let's see, 8 months--he must be crawling all over the place by now!" The prize goes as usual to my mother-in-law, who would ask if the baby was crawling yet, and then tell me AGAIN that children who crawl late tend to have learning disabilities. (Whuh? Even if this were true, why would she say so?)
And how should you deal with this sort of, um, concern? You could try hooking a leg behind the other person's ankles and giving a sudden sharp shove, as I fantasized doing many a time. Or, you can act surprised right back at them: "Well, no! But she's only 13 months!" (tone of voice communicates "Do you have a fever or something?").
For people who have genuine concern rather than the faked concern designed to make you feel bad, you can say that the pediatrician says there's a wide range of normal, and that he or she says your child is still well within that range. The words "well within" are not only comforting but also pointed: they communicate that not only is the concern unnecessary, it's a little on the ignorant side. You can look at them pityingly, give a little laugh and say, "Don't worry! I would tell you if there was anything wrong!" Like THEY'RE the big old worrywarts, while you yourself are laid-back and calm and definitely not lying awake at night fretting about how a larval child like yours will be able sit up at a desk.
Now. Perhaps you could chime in with your reassurances for Cari. Late bloomers who ended up fine or better than fine? (Or, sure, why not: early bloomers who ended up in prison and/or on drugs?)