My daughter is 11 1/2 months old. She's been in the 95 percent range in growth (height and weight) until she was 9 months old. However, she has not grown since her last checkup. Should I be concerned?
In general, babies are frequently weighed and measured throughout the first months (and years) in order to make sure they are following an expected pattern of growth. This is useful, because we have growth curves available that tell us what is a typical rate of growth, and what height or weight is typical at any given age. As you've already discovered, not all babies (nor adults) are 50th percentile. Rather, some are bigger and some are smaller. What really matters is if a child who is 95th percentile continues to grow at the predicted rate (also expressed as "growing along the 95th percentile" on the growth curve).
That being said, parents often express concern about whether their children are "keeping up with their curves"—especially as their babies enter toddlerhood. Whenever there's a question of whether a child has stopped growing, the first thing to do is not only check height and weight, but to plot them on the growth curve. The reason I suggest this first is because children's rate of growth predictably slows down towards the end of the first year, and this slow-down can catch unaware parents quite by surprise. In other words, a one year old may seem to their parents like they're hardly gaining any weight in comparison to months past when it's entirely possible that their rate of growth is on target.
In instances where a child is truly falling behind on growth (ie "falling off" his/her established growth curve), it's well worth checking in with your pediatrician to do such things as get a current height and weight, plot it on your child's growth curve, consider if there are any nutritional issues, and determine whether there have been any recent illnesses or other causes that can affect growth. In the case of recent illnesses, for example, it is not uncommon for kids to occasionally lose some ground on their growth curves during an illness, but then typically gain it back soon after.
With all that in mind, rather than being concerned, you should partner with your pediatrician, take a closer look at your daughter's curves (and her circumstances), and then figure out together whether any sort of additional measures need to be taken.