How common is bullying in swimming clubs?

[Taxing]

My daughter, who is 11, has recently been moved up into the top group of her swimming club after some fairly good swims and a major improvement in the 800m timed swim.

She has though started to suffer bullying from girls older, but not as fast, as her.

Is this a common occurence? I have made representations to the coaching team who are, to be fair, looking into things and are already taking steps to improve general discipline