Assuming this is for the 2024-2025 season, it's her age as of 12/31/25, so yes, she would be 8 years old.
However, at most meets by us, they take the total number of competitors and divide them into even age groups. For ease, let's say there are 30 athletes. The 10 youngest would be a group, the next 10 oldest, and then the oldest 10 would be the last age group. In this situation, if your daughter was that 11th youngest athlete, it would bump her into the next group. And yes, an athlete who might win in one age group might not place in another, and I know it sucks sometimes, but that's just how it is. It's why, as a coach, I discourage goals that center around placing or even scores and focus on things a gymnast has control over - did you stay on the beam? Did you connect your bar routine? Were your feet pointed through your leap series?
As for not being scored initially or being on the website, mistakes happen and you'll find the scoring websites are not the end all be all. They will have missing data a lot, they will crash, they won't update immediately. Please just try to be your kiddo's number one fan and help her learn to try her best, be a good teammate, and have fun in sport.