If she's getting the same "amount" of flow +/-, and the path hasn't changed due to the pond you built, then it's likely she has very little chance at a case. However, if her use of the berm backs up water on to your land and/or altering normal flow, she could be in for a legal awakening... and possibly a costly bill.

12 ac pond in NW Missouri. 28' max depth at full pool. Fish Present: LMB, BG, RES, YP, CC, WB, HSB, WE, BCP, WCP, GSH.