Youth board size

Just wondering if height to board size matters much? I looked up youth sizing & the consensus was a 131cm for a 100 pound kid would be excellent, I expect her to jump another 10 pounds over summer with growth. But the board is up to her forehead if not an inch bigger. Is that a problem?

She could probably ride a shorter board but it sounds like she will grow into this one. Also at cable parks people tend to ride longer boards whereas behind the boat can be shorter because you usually go faster.